<PAGE>

   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 23, 1999

                         REGISTRATION NO. 333-_______

                      SECURITIES AND EXCHANGE COMMISSION



                                   FORM S-3
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
                           ------------------------

                              ORGANOGENESIS INC.
            (Exact name of registrant as specified in its charter)

     DELAWARE                                     04-2871690
(State or other jurisdiction of                  (I.R.S. Employer
incorporation or organization)                  Identification No.)


                   HERBERT M. STEIN, CHIEF EXECUTIVE OFFICER
                              ORGANOGENESIS INC.
                                 150 DAN ROAD
                          CANTON, MASSACHUSETTS 02021
                                (781) 575-0775
     (Address, including zip code, and telephone, including area code, of
                   registrant's principal executive offices)

                                   COPY TO:

                           NEIL H. ARONSON, ESQUIRE
              MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C.
                             ONE FINANCIAL CENTER
                         BOSTON, MASSACHUSETTS  02111
                                (617) 542-6000
                           ------------------------

Approximate date of commencement of proposed sale to the public:  As soon as
practical after this Registration Statement becomes effective.
If the only securities being registered on this Form are being offered pursuant
to dividend or interest reinvestment plans, please check the following box. [_]

If any of the securities being registered on this Form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933 other than securities offered only in connection with dividend or interest
reinvestment, check the following box.                                      [X]

If this Form is filed to register additional securities for an offering pursuant
to Rule 462(b) under the Securities Act, please check the

following box and list the Securities Act registration statement number of the
earlier effective registration statement for the same offering.             [_]

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under
the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering.                                                      [_]

If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box.                                             [_]

                                   __________

                        Calculation of Registration Fee
<TABLE>
<CAPTION>

                                                          Proposed          Proposed
                                                          maximum           maximum
Title of each                                             offering          aggregate         Amount of
class of securities                  Amount to be         price per         offering          registration
to be registered                     registered           share             price             fee  (1)
-------------------------------------------------------------------------------------------------------------
<S>                                 <C>                   <C>               <C>               <C>

Debt Securities (2), Preferred
Stock and Common Stock, $.01 par
value per share (3)                         (4)              (4)           $50,000,000         $13,200.00(5)
-------------------------------------------------------------------------------------------------------------

Total Registration Fee                                                                         $13,200.00
-------------------------------------------------------------------------------------------------------------
</TABLE>
(1)  Estimated solely for the purpose of calculating the amount of the
     registration fee in accordance with Rule 457(i) of the Securities Act of
     1933.  The aggregate initial public offering price of the securities
     registered hereby will not exceed $50,000,000 in U.S. dollars or the U.S.
     dollar equivalent in foreign currency or currency units.
(2)  May be issued at original issue discount.
(3)  Includes associated Preferred Share Purchase Rights, which initially are
     attached to and trade with the shares of Common Stock being registered
     hereby.  The value attributable to such Preferred Share Purchase Rights, if
     any, is reflected in the market price of the Common Stock.
(4)  The amount to be registered and the proposed maximum offering price have
     been omitted pursuant to Rule 457(o) of the Securities Act of 1933.
(5)  The registration fee has been calculated pursuant to Rule 457(o) under the
     Securities Act of 1933.

  The registrant hereby amends this registration statement on such date or dates
as may be necessary to delay its effective date until the registrant shall file
a further amendment which specifically states that this registration statement
shall thereafter become effective in accordance with section 8(a) of the
Securities Act of 1933 or until the registration statement shall become
effective on such date as the commission, acting pursuant to said section 8(a),
shall determine.
<PAGE>

THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE MAY
NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER
TO SELL THESE SECURITIES AND IS NOT SOLICITING AN OFFER TO BUY THESE SECURITIES
IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.

                                  PROSPECTUS

                    Subject to Completion, dated __________

                              ORGANOGENESIS INC.

                                  $50,000,000
                                Debt Securities
                                Preferred Stock
                                 Common Stock
 (We will not issue in excess of 3,000,000 shares of our common stock, either
directly or upon conversion of any convertible securities, sold pursuant to this
                                  Prospectus)


This Prospectus is part of a Registration Statement we filed with the Securities
and Exchange Commission using a "shelf" registration process.  This means:


 .  We may issue debt securities, shares of            -------------------------
   preferred stock and/or shares of common
   stock from time to time at an aggregate
   initial public offering price not to exceed         This Investment Involves
   $50,000,000 (or the equivalent if debt               A High Degree of Risk.
   securities are denominated in one or more             You Should Purchase
   foreign currencies) and not to exceed                    Shares Only If
   3,000,000 shares of our common  stock (or                You Can Afford
   securities convertible into our common                   A Complete Loss.
   stock).
 .  We will circulate a Prospectus Supplement
   each time we issue the debt securities,
   preferred stock and/or common stock.
 .  The Prospectus Supplement will inform you
   about the specific terms of that offering
   and also may add, update or change
   information contained in this Prospectus.
 .  You should read this Prospectus and any
   Prospectus Supplement carefully before you
   invest.


                                                          See "Risk Factors"
                                                         Beginning on Page 4.

                                                      -------------------------


                                                      -------------------------

  Our Common Stock is traded on the American Stock Exchange under the symbol
                                    "ORG".
    On December 20, 1999, the last reported sale price for the Common Stock
             on the American Stock Exchange was $9.125 per share.

Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete.  It is illegal for any person to tell you
otherwise.

The information in this prospectus is not complete and may be changed.  A
registration statement relating to these securities has been filed with the
Securities and Exchange commission. No one may sell these securities nor may
offers to buy be accepted until the registration statement filed with the
Securities and Exchange Commission is effective.  This prospectus is not an
offer to sell these securities and is not soliciting an offer to buy these
securities in any state where the offer, solicitation or sale is not permitted.

                THE DATE OF THIS PROSPECTUS IS DECEMBER __, 1999
<PAGE>

                      WHERE YOU CAN FIND MORE INFORMATION

     We are a public company and file annual, quarterly and special reports,
proxy statements and other information with the Securities and Exchange
Commission. You may read and copy any document we file at the SEC's Public
Reference Room at 450 Fifth Street, N.W., Washington, D.C. 20549. You can
request copies of these documents by writing to the SEC and paying a fee for the
copying cost. Please call the SEC at 1-800-SEC-0330 for more information about
the operation of the public reference room. Our SEC filings are also available
to the public at the SEC's web site at "http://www.sec.gov." In addition, our
stock is listed for trading on the American Stock Exchange. You can read and
copy reports and other information concerning us at the offices of the American
Stock Exchange located at 86 Trinity Place, New York, New York 10006-1881.

     This prospectus is only part of a Registration Statement on Form S-3 that
we have filed with the SEC under the Securities Act of 1933 and therefore omits
certain information contained in the Registration Statement. We have also filed
exhibits and schedules with the Registration Statement that are excluded from
this prospectus, and you should refer to the applicable exhibit or schedule for
a complete description of any statement referring to any contract or other
document. You may:

     .    inspect a copy of the Registration Statement, including the exhibits
          and schedules, without charge at the public reference room or
     .    obtain a copy from the SEC upon payment of the fees prescribed by
          the SEC.

                    INCORPORATION OF DOCUMENTS BY REFERENCE

     The SEC allows us to "incorporate by reference" the information we file
with it, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be a part of this prospectus and information that we file later
with the SEC will automatically update and supersede this information. We
incorporate by reference the documents listed below and any future filings made
with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange
Act of 1934 until all of the shares of common stock are sold. The documents we
are incorporating by reference are:

     .    Our Annual Report on Form 10-K for the fiscal year ended December
          31, 1998, filed on March 31, 1999 (File No. 1-09898);

     .    Our Quarterly Reports on Form 10-Q for the quarters ended March 31,
          1999, June 30, 1999, and September 30, 1999 filed on May 14, 1999,
          August 16, 1999, and November 15, 1999, respectively;

     .    Our Proxy Statement, filed on April 21, 1999; and

     .    The description of our capital stock contained in our registration
          statements on Form 8-A under the 1934 Act (File No. 1-09898),
          including amendments or reports filed for the purpose of updating that
          description.

     You may request a copy of these filings at no cost by writing or
telephoning our Director of Investor and Public Relations at the following
address and phone number:

          Organogenesis Inc.
          150 Dan Road
          Canton, Massachusetts   02021
          (781) 575-0775

     This prospectus is part of a Registration Statement that we filed with the
SEC. You should rely only on the information incorporated by reference in or
provided in this prospectus and the Registration Statement.

                                       3
<PAGE>

We have not authorized any other person to provide you with different
information. We are not making an offer of these securities in any state where
the offer is not permitted. You should not assume that the information in this
prospectus is accurate as of any date other than the date on the front of this
document.

     CERTAIN PERSONS PARTICPATING IN AN OFFERING MAY ENGAGE IN TRANSACTIONS THAT
STABILIZE, MAINTAIN OR OTHERWISE AFFECT THE PRICE OF THE SECURITIES, INCLUDING
OVER-ALLOTMENT, STABILIZING AND SHORT-COVERING TRANSACTIONS IN SUCH SECURITIES,
AND THE IMPOSITION OF A PENALTY BID, AND BIDIDNG FOR AND PURCHASING SHARES OF
THE COMMON STOCK IN THE OPEN MARKET DURING AND AFTER AN OFFERING.

                                       4
<PAGE>

                               PROSPECTUS SUMMARY

     This summary highlights information incorporated by reference or contained
elsewhere in this prospectus. It is not complete and may not contain all of the
information that you should consider before investing in our securities. You
should read the entire prospectus carefully, including the "Risk Factors"
section, and you must consult the more detailed financial statements, and notes
to financial statements, incorporated by reference in this prospectus.

          This prospectus and the documents incorporated by reference contain
forward-looking statements. These statements can be identified by the use of
forward-looking terminology such as "may," "will," "could," "expect,"
"anticipate," "estimate," "continue" or other similar words. These statements
discuss future expectations, contain projections of results of operations or of
financial condition or state other forward-looking information. Examples of
forward-looking statements can be found in the discussion set forth under
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" in our Annual Report on Form 10-K for the fiscal year ended December
31, 1998 and under "Business" in the Form 10-K, incorporated in this prospectus
by reference. Such statements are based on current expectations that involve a
number of uncertainties including those set forth in the risk factors below.
When considering forward-looking statements, you should keep in mind that the
risk factors noted below and other factors noted throughout this prospectus or
incorporated by reference could cause our actual results to differ significantly
from those contained in any forward-looking statement.

                                  THE COMPANY

     Organogenesis Inc. designs, develops and manufactures medical therapeutics
containing living cells and/or natural connective tissue.  We were formed to
advance and apply the emerging field of tissue engineering to major medical
needs.  We were organized as a Delaware corporation in 1985, with our principal
executive offices located at 150 Dan Road, Canton, Massachusetts 02021. Our
telephone number is 781-575-0775.

     Tissue-engineered products typically include living cells and/or natural
connective tissue material such as collagen.  Living cells can produce or remove
substances in response to their environment; connective tissue can provide
physical function while being converted to living tissue through the ingrowth of
a patient's cells and blood vessels.  We have established expertise with both
mammalian (e.g., human) cells and natural connective tissue and select our
product development approach based upon medical applications.  We target
applications  in which our products have the potential to provide significant
benefits over traditional approaches and the ability to achieve the necessary
economies of scale for cost-effectiveness.   Our product development program
includes living tissue replacements (such as Vitrix), cell- based organ assist
devices (such as our Bioartificial Liver) and other tissue-engineered products
(such as our vascular graft product).  Our product pipeline includes both
products which include living cells, and purely acellular, connective tissue-
based products. We are also exploring additional opportunities relating to cell
and gene therapy applications and to our cryopreservation technology.

     We have established expertise in procuring, culturing and optimizing human
cells to provide cell function in tissue-engineered products.  Our lead product,
Apligraf(R)*, was launched in the United States - the world's largest healthcare
market - in June 1998. Apligraf is the only manufactured product containing
living human cells to show efficacy in a controlled study and to gain FDA PMA
approval. Apligraf is approved for use by the FDA in the treatment of venous leg
ulcers.  In December 1999, the Company submitted an Apligraf PMA supplement for
diabetic foot ulcers.

     Our strategy is to commercialize products either by ourselves or through
partners with an established marketing presence. For example, Novartis Pharma AG
has global marketing rights to Apligraf and is responsible for sales and
marketing costs. We have an active business development program related to
products and technologies in our pipeline.

* Apligraf(R) is a registered mark of Novartis Pharma AG.

                                       5
<PAGE>

                                  Risk Factors

     Before you purchase our securities, you should be aware that there are
risks, including those described below. You should consider carefully these risk
factors together with all of the other information contained elsewhere in this
prospectus or incorporated by reference before you decide to purchase our
securities.

Our Company Has a History of Losses

     Organogenesis Inc. was founded in 1985. We have incurred operating losses
in every year of our existence.  We incurred net losses of $7,499,000 for the
year ended December 31, 1996, $19,807,000 for the year ended December 31, 1997,
$14,031,000 for the year ended December 31, 1998, and $19,996,000 for the nine
months ended September 30, 1999, which losses are continuing. As of September
30, 1999, we have an accumulated deficit of $121,013,000. We have not achieved
profitability and expect to continue to incur net losses. The extent of future
losses and the time required to achieve profitability is highly uncertain.
Moreover, although our business is not seasonal in nature, our revenues tend to
vary significantly from fiscal quarter to fiscal quarter.

In Order to Achieve Commercial Success, Our Products Must Gain Market Acceptance

     We manufacture and market one principal product: Apligraf. We have only
recently begun to market Apligraf through Novartis and to generate revenues from
the commercialization of this product. Products under development will require
additional research and development efforts, including clinical testing and
regulatory approval, prior to commercial use. Our potential products are subject
to the risks of failure inherent in the development of medical products based on
new technologies. These risks include the possibilities that:

     .    Our approach will not be successful;
     .    Our potential products will be found to be unsafe, ineffective or
          otherwise will fail to meet applicable regulatory standards or receive
          necessary regulatory clearances;
     .    The potential products, if safe and effective, will be difficult to
          develop into commercially-viable products, will be difficult to
          manufacture on a large scale, will be uneconomical to market, or will
          fail to obtain acceptance by the medical community;
     .    Proprietary rights of third parties will preclude us from marketing
          such products; or
     .    Third parties will market superior or equivalent products.

     Our business results would be hurt if were unable to demonstrate to the
medical community the efficacy, relative safety and cost effectiveness of
treating patients with our products or if our products were not accepted as
alternatives to other existing or new therapies.

Our Markets Are Competitive

     We are engaged in the rapidly evolving and competitive field of tissue
engineering for the treatment of skin wounds and other medical needs. Our
competitors include tissue engineering companies, xenotransplant companies,
wound care divisions of major pharmaceutical companies and other pharmaceutical,
biotechnology and medical products companies using traditional technologies to
develop products for wound care. Some of these companies have much greater
resources, research and development staffs and facilities, experience in
conducting clinical trials and obtaining regulatory approvals and experience in
the manufacturing, marketing and distribution of products than we do. Our
competitive position is based upon our ability to (1) create and maintain
scientifically-advanced technology and proprietary products and processes, (2)
attract and retain qualified personnel, (3) obtain patent or other protection
for our products and processes, (4) obtain required government approvals on a
timely basis, (5) manufacture products on a cost-effective basis and (6)
successfully market products. If we are not successful in meeting these goals,
our business could be hurt. Similarly, our competitors may succeed in developing

                                       6
<PAGE>

technologies, products or procedures that are more effective than any that we
are developing or that would render our technology and products obsolete,
noncompetitive or uneconomical.

We Depend Upon Strategic Relationships to Market Our Products

     We have limited experience in sales, marketing and distribution. We will
need to develop long-term strategic relationships with partners, such as
Novartis, that have marketing and sales forces with technical expertise and
distribution capability. To the extent that we enter into such relationships,
our revenues will depend upon the efforts of third parties who may or may not be
successful. We may not be able to establish or maintain long-term strategic
relationships, and if we do, our collaborators may not be successful in gaining
market acceptance for our products. To the extent that we choose not to or are
unable to negotiate or maintain collaborations, we will need more capital and
resources to undertake a commercialization program at our own expense. In
addition, we may encounter significant delays in introducing our products into
certain markets or find that the commercialization of products in such markets
may be adversely affected by the absence of collaborative agreements. We are
dependent on Novartis for the successful marketing and selling of Apligraf
worldwide. If Novartis does not succeed in marketing and selling Apligraf or
gaining international approvals for the product or if we are unable to meet the
production demand of global commercialization, our operating results will
suffer.

Our Ability to Commercialize Our Products Depends Upon Our Compliance with
Government Regulations

     Our present and proposed activities are subject to extensive and rigorous
regulation by governmental authorities in the US and other countries. To
clinically test, produce and market medical devices for human use, we must
satisfy mandatory procedural and safety and efficacy requirements established by
the FDA and comparable state and foreign regulatory agencies. Typically, such
rules require that products be approved by the government agency as safe and
effective for their intended use prior to being marketed. The approval process
is expensive, time consuming and subject to unanticipated delays. Our product
candidates may not be approved. In addition, our product approvals could be
withdrawn for failure to comply with regulatory standards or due to unforeseen
problems after the product's marketing approval.

     Testing is necessary to determine safety and efficacy before a submission
may be filed with the FDA to obtain authorization to market regulated products.
In addition, the FDA imposes various requirements on manufacturers and sellers
of products under its jurisdiction, such as labeling, Good Manufacturing
Practices, record keeping and reporting requirements. The FDA also may require
post-marketing testing and surveillance programs to monitor a product's effects.
Furthermore, changes in existing regulations or the adoption of new regulations
could prevent us from obtaining, or affect the timing of, future regulatory
approvals or could negatively affect the marketing of our existing products. If
(1) the regulatory agencies find our testing protocols to be inadequate, (2) the
appropriate authorizations are not granted on a timely basis, or at all, (3) the
process to obtain authorization takes longer than expected or we have
insufficient funds to pursue such approvals, (4) we lose previously-received
authorizations or (5) we do not comply with regulatory requirements, we would
not be able to commercialize our products as planned and our operating results
would be hurt.

     Medical and biopharmaceutical research and development involves the
controlled use of hazardous materials, such as radioactive compounds and
chemical solvents. We are subject to federal, state and local laws and
regulations governing the use, manufacture, storage, handling and disposal of
such materials and waste products. In addition, we handle and dispose of human
tissue. Although we believe that our safety procedures for handling these
materials are adequate, if accidental contamination or injury were to occur, we
could be liable for damages.

We Rely Heavily Upon Our Patents and Proprietary Technology

     We rely upon our portfolio of patent rights, patent applications and
exclusive licenses to patents and patent applications relating to living tissue
products, organ assist treatments and other aspects of tissue engineering. We

                                       7
<PAGE>

currently have 22 patents issued or allowed in the US, 11 pan-European patents
issued or granted and six patents issued in Japan. As part of our continuing
interest in protecting intellectual property rights, we have filed and are
prosecuting 16 other patent applications in the US. We also license some of our
technologies under an exclusive patent license agreement with the Massachusetts
Institute of Technology. The agreement with MIT covers certain US patents and
corresponding patents in Europe and Japan. Pursuant to the MIT agreement, we
have been granted an exclusive, worldwide license to make, use and sell the
products covered by the patents and to practice the procedures covered by the
patents.

     We expect to aggressively patent and protect our proprietary technologies.
However, we cannot be sure that any additional patents will be issued to us as a
result of our domestic or foreign patent applications or that any of our patents
will withstand challenges by others. Patents issued to or licensed by us may be
infringed or third parties may independently develop either the same or similar
technology. Similarly, our patents may not provide us with meaningful protection
from competitors, including those who may pursue patents which may prevent,
limit or interfere with our products or will require licensing and the payment
of significant fees or royalties by us to such third parties in order to enable
us to conduct our business. We may sue or be sued by third parties regarding
patents and other intellectual property rights. These suits are costly and would
divert funds and management and technical resources from our operations.

     We also rely upon unpatented proprietary technology, know-how and trade
secrets and seek to protect them through confidentiality agreements with
employees, consultants and advisors. We request that any corporate sponsor with
which we enter into a collaborative agreement do so as well. If these
confidentiality agreements are breached, we may not have adequate remedies for
the breach. In addition, others may independently develop or otherwise acquire
substantially the same proprietary technology as our technology and trade
secrets.

     We have relationships with a number of academic consultants who are not
employed by us. Accordingly, we have limited control over their activities and
can expect only limited amounts of their time to be dedicated to our activities.
These persons may have consulting, employment or advisory arrangements with
other entities that may conflict with or compete with their obligations to us.
Our consultants typically sign agreements that provide for confidentiality of
our proprietary information and results of studies. However, in connection with
every relationship, we may not be able to maintain the confidentiality of our
technology, the dissemination of which could hurt our competitive position and
results of operations. To the extent that our scientific consultants develop
inventions or processes independently that may be applicable to our proposed
products, disputes may arise as to the ownership of the proprietary rights to
such information, and we may not win those disputes.

We Must Be Able to Manufacture Our Products Successfully and Obtain Adequate
Sources of Supply

     The process of manufacturing our products is complex, requiring strict
adherence to manufacturing protocols. We have been producing our lead product,
Apligraf, for commercial sale since the second half of 1997 in adherence with
these manufacturing protocols. However, with increasing demand for Apligraf, we
must further transition from small-scale to full-scale production of our
products. If we do not make the full transition successfully, we will not be
able to satisfy the demands for our products and our results of operations will
be hurt.

     We are required to maintain a manufacturing facility in compliance with
Good Manufacturing Practices. Manufacturing facilities and processes pass an
inspection before the FDA issues any product licenses necessary to market
medical therapeutics and are subject to continual review and periodic
inspection. We may not be able to maintain the necessary regulatory approvals
for our manufacturing operations or manufacture our products in a cost-effective
manner. If we were unable to manufacture potential products independently or
obtain or retain third party manufacturing on commercially-acceptable terms, the
submission of products for final regulatory approval and initiation of marketing
would be delayed. This, in turn, may cause us to be unable to commercialize
product candidates as planned, on a timely basis or on a profitable basis.

                                       8
<PAGE>

     We manufacture Apligraf for commercial sale, as well as for use in clinical
trials, at our Canton, Massachusetts facility. Among the fundamental raw
materials needed to manufacture Apligraf are keratinocyte and fibroblast cells.
Because these cells are derived from donated infant foreskin, they may contain
human-borne pathogens. We perform extensive testing of the cells for pathogens,
including the HIV or "AIDS" virus. Our inability to obtain cells of adequate
purity, or cells that are pathogen-free, would limit our ability to manufacture
sufficient quantities of our products.

     Another major material required to produce our products is collagen, a
protein obtained from animal source tissue. We have developed a proprietary
method of procuring our own collagen that we believe is superior in quality and
strength to collagen available from commercial sources. We currently obtain
animal source tissue from US suppliers only. We may not be able to obtain
adequate supplies of animal source tissue to meet our future needs or on a cost-
effective basis. The thermo-formed tray assembly that is used in the
manufacturing process of Apligraf is available to us under a supply arrangement
with only one manufacturing source. Because the FDA approval process requires
manufacturers to specify their proposed materials of certain components in their
applications, FDA approval of a new material would be required if a currently-
approved material became unavailable from a supplier. If we are unable to obtain
adequate supplies of thermo-formed tray assemblies to meet future Apligraf
manufacturing needs or if we cannot obtain such assemblies on a cost-effective
basis, our operations would be hurt.

     Interruptions in our supply of materials may occur in the future or we may
have to obtain substitute vendors for these materials. Any significant supply
interruption would adversely affect the production of Apligraf. In addition, an
uncorrected impurity or a supplier's variation in a raw material, either unknown
to us or incompatible with our manufacturing process, could hurt our ability to
manufacture products.


The Retention of Key Personnel Is Important to Our Competitive Position

     Because of the specialized nature of our business, our success will depend
upon our ability to attract and retain highly-qualified personnel and to develop
and maintain relationships with leading research institutions. The competition
for those relationships and for experienced personnel amongst the biotechnology,
pharmaceutical and healthcare companies, universities and non-profit research
institutions is intense. If we are unable to continue to attract and retain such
personnel or relationships, our competitive position could be hurt.

We May Be Subject to Product Liability Suits; Our Insurance May Not Be
Sufficient to Cover Damages

     Our business exposes us to potential liability risks that are inherent in
the testing, manufacturing, marketing and sale of medical products. The use of
our products and product candidates, whether for clinical trials or commercial
sale, may expose us to product liability claims or product recall and possible
adverse publicity. Although we have product liability insurance coverage, the
level or breadth of our coverage may not be adequate to fully cover potential
liability claims. In addition, we may not be able to obtain additional product
liability coverage in the future at an acceptable cost. A successful claim or
series of claims brought against us in excess of our insurance coverage and the
effect of product liability litigation upon the reputation and marketability of
our technology and products, together with the diversion of the attention of key
personnel, could negatively affect our business.

Our Business Is Subject to the Uncertainty of Third-Party Reimbursement and
Health Care Reform Measures Which May Limit Market Acceptance

     In both domestic and foreign markets, our ability to commercialize our
product candidates will depend, in part, upon the availability of reimbursement
from third-party payors, such as government health administration authorities,
private health insurers and other organizations. Third-party payors are
increasingly challenging the price and cost-effectiveness of medical products.
If our products are not considered cost-effective, third-party

                                       9
<PAGE>

payors may limit reimbursement. Government and other third-party payors are
increasingly attempting to contain healthcare costs by limiting both coverage
and the level of reimbursement for new therapeutic products approved for
marketing by the FDA and by refusing, in some cases, to provide any coverage for
uses of approved products for disease indications for which the FDA has not
granted marketing approval. If government and third-party payors do not provide
adequate coverage and reimbursement levels for uses of our products, the market
acceptance of our products would be limited.

     There have been a number of federal and state proposals during the last few
years to subject the pricing of pharmaceuticals to government control and to
make other changes to the health care system of the US. It is uncertain what
legislative proposals will be adopted or what actions federal, state or private
payors for health care goods and services may take in response to any health
care reform proposals or legislation. We cannot predict the effect health care
reforms may have on our business.

Our Stock Price Is Volatile

     The biotechnology sector seems particularly vulnerable to abrupt changes in
investor sentiment. Stock prices of companies in the biotechnology industry,
including ours, can swing dramatically, with little relationship to operating
performance. Our stock price may be affected by a number of factors including,
but not limited to, (1) clinical trial results and other product development
events, (2) the outcome of litigation, (3) decisions relating to intellectual
property rights, (4) the entrance of competitive products into our market, (5)
changes in reimbursement policies or other practices related to the
pharmaceutical industry or (6) other industry and market changes or trends.

If We Are Unable to Raise Needed Funds, Your Investment Could Be Adversely
Affected

     Based upon our current plans, we believe that existing working capital and
future funds from Novartis, including product and royalty revenue, will be
sufficient to finance operations into 2000. We will need additional capital
within the next year to continue under the current plan. However, this statement
is forward-looking and changes may occur that would significantly decrease
available cash before such time. Factors that may change our cash requirements
include:

 .  Delays in obtaining regulatory approvals of products in different countries,
if needed, and subsequent timing of product launches;
 .  Delays in commercial acceptance and reimbursement when product launches
occur;
 .  Changes in the progress of research and development programs;
 .  Changes in the resources devoted to outside research collaborations or
projects, self-funded projects, proprietary manufacturing methods and advanced
technologies; and
 .  Acquisition of a second manufacturing plant.

   Any of these events could adversely impact our capital resources, requiring
us to raise additional funds. Additional funds may not be available when
required on acceptable terms. If adequate funds are not available when needed,
we would need to delay, scale back or eliminate certain research and development
programs or license to third parties certain products or technologies that we
would otherwise undertake ourselves, resulting in a potential material adverse
effect on our financial condition and results of operations.

Our Anti-Takeover Measures May Affect the Value of Our Stock

     We, as a Delaware corporation, are subject to the General Corporation Law
of the State of Delaware, including Section 203, an anti-takeover law enacted in
1988. In general, Section 203 restricts the ability of a public Delaware
corporation from engaging in a "business combination" with an "interested
stockholder" for a period of three years after the date of the transaction in
which the person became an interested stockholder. As a result of the
application of Section 203 and certain provisions in our certificate of
incorporation and bylaws, potential acquirors

                                       10
<PAGE>

may be discouraged from attempting to acquire us, thereby possibly depriving our
stockholders of acquisition opportunities to sell or otherwise dispose our stock
at above-market prices typical of such acquisitions.

     We have also adopted a shareholder rights plan which gives holders of
common stock the right to purchase shares of our Series B Junior Participating
Preferred Stock if a potential acquiror purchases or plans to make a tender
offer to purchase 15% or more of our outstanding common stock. The existence of
this plan may make it more difficult for a third party to acquire control of us.

     We are authorized to issue up to 1,000,000 shares of preferred stock, $.01
par value per share and to determine the price, privileges and other terms of
such shares. The issuance of any preferred stock with superior rights to the
common stocks could reduce the value of the common stock. In particular,
specific rights granted to future holders of preferred stock could be used to
restrict our ability to merge with or sell our assets to a third party, thereby
preserving control of Organogenesis by present owners and management and
preventing our holders of common stock from realizing a premium on their shares.

The Value Of Your Securities May Decrease If Other Security Holders Exercise
Their Options and Warrants or Convert Their Debt Into Common Stock or If Other
Stockholders Sell Their Stock

     As of December 20, 1999, 30,689,019 shares of our common stock are
outstanding (excluding 60,000 treasury shares). We have reserved an additional
12,312,475 shares of common stock for future issuance upon exercise or
conversion of options, warrants, the Series C convertible preferred stock and
the convertible debentures. We plan to issue additional options and warrants in
the future.  If any of these securities are exercised or converted, you may
experience significant dilution in the market value and earnings per share of
the common stock into which your securities are convertible.

     In March 1998, we completed a $20 million convertible preferred stock and
warrant financing with two institutional investors. The Series C preferred stock
pay no dividends, have no voting rights, and are convertible into common stock
on a scheduled basis over two years based on market price at time of conversion
(up to $28.80 per share). We may call for conversion of all or part of the
shares of Series C preferred stock under certain conditions based on continued
improvement in the price of our common stock. Conversions by the investors are
subject to certain limits; no limits exist for conversions on redemption or upon
a major transaction. Mandatory conversion is March 26, 2000, at which time we
have the option to redeem any outstanding Series C preferred shares in cash or
by issuing common stock. In addition, the investors received three-year warrants
to purchase an aggregate of 200,000 shares of common stock at $31.20 per share.
The warrants may be exercised at any time prior to April 2001. In July 1998, the
investors exercised their right to receive additional warrants to purchase
150,000 shares of common stock at $17.45 per share with an expiration date of
March 26, 2001. We also issued a warrant to purchase an aggregate of 50,000
shares of common stock at $28.80 per share to the placement agent that expires
March 25, 2001. No further warrants may be issued under the Series C preferred
stock placement. In April 1998, we filed a registration statement for 1,800,000
shares of common stock, the maximum number of shares that may be acquired
relating to this transaction; except for mandatory conversion where the common
share limit does not apply. All shares have been reserved for issuance. The SEC
declared this registration statement effective in May 1998. In May, September
and November 1998, an aggregate of $13,800,000 face amount of the Series C
preferred stock was converted into common stock resulting in the issuance of
approximately 1,136,000 shares of common stock.

     We closed a $20 million convertible debt and warrant financing at the end
of March 1999. The convertible debt accrues interest at 7% annually and is
convertible into common stock at a fixed price of $14.50 per share at any time
after March 30, 2000 and through March 29, 2004. Subject to meeting specified
conditions, at our option, any time on or after March 30, 2002, we may prepay
all of the outstanding principal by converting the outstanding principal to
common stock at $14.50 per share and we may pay accrued interest on the debt by
paying cash or by converting the outstanding interest into shares of common
stock (at the average trading price for our common stock for the twenty trading
days preceding the interest payment date). In addition, the purchasers of the
convertible debt

                                       11
<PAGE>

received five-year warrants to purchase up to 400,000 shares of common stock at
$21.75 per share. The warrants may be exercised upon 75 days' prior written
notice at any time prior to March 29, 2004. In May 1999, we filed a registration
statement for 2,096,333 shares of Common Stock issuable as follows: (1)
1,646,333 shares of Common Stock which may become issuable by reason of the
conversion of the convertible debt, and accrued interest, (2) 400,000 shares
which may become issuable upon the exercise of the warrants issued in the
financing, and (3) 50,000 shares issued in connection with an asset purchase
transaction. In May 1999, the SEC declared this registration statement
effective.

     If our stockholders sell substantial amounts of our common stock in the
public market following this offering, the market price of our common stock
could fall. Such sales also might make it more difficult for us to sell equity
or equity-related securities in the future at a price we deem appropriate.

We Have No Intention to Pay Dividends

     We have never paid any cash dividends on our common stock.  We currently
intend to retain all future earnings, if any, for use in our business and do not
expect to pay any dividends in the foreseeable future.

Our Business Is Exposed to the Risk of System Failure from the Year 2000
Problem

     The Year 2000 issue ("Y2K") refers to potential problems with computer
systems or any equipment with computer chips or software that use dates where
the year has been stored as just two digits (e.g., 98 for 1998). On January 1,
2000, any clock or date recording mechanism incorporating date sensitive
software which uses two digits to represent the year may recognize a date using
00 as the year 1900 rather than the year 2000.  This could result in a system
failure or miscalculations causing disruption of operations, including, among
other things, a temporary inability to manufacture product or process
transactions, send invoices or engage in similar business activities.

     In order to address this situation, we conducted an assessment to identify
and determine the Y2K readiness of our systems.  This assessment program focused
on three main functional areas, including:

  .    Information technology which addresses data, phone and administrative
       systems;

  .  Embedded chip technology which addresses manufacturing systems, laboratory
     instruments and plant maintenance systems with programmable logic
     controllers with date functions; and

  .  Material suppliers, vendors and other third parties that address areas that
     are critical to the manufacturing process, distribution of product or other
     business processes.

     The task of assessment from a Y2K readiness perspective is 100% complete
and remedial action for noncompliant systems is complete. In addition to the
assessment of systems, key vendors, suppliers and other third parties were
identified and a survey form was sent to each of these business entities to
determine if their systems are Y2K compliant. We have received responses from
all of our critical vendors, suppliers, and other third parties. Y2K issues with
our vendors, suppliers or other third parties could delay the shipment and
receipt of critical supplies, potentially impacting production and operations.
We proactively addressed the Y2K issue with vendors, suppliers and other third
parties to minimize risk from these external factors.

     Our Y2K project is complete and the costs associated with the Y2K issue was
about $250,000, which included the use of internal resources. Working capital
was used to fund these costs. Costs consisted primarily of payroll costs for
existing employees, including the information technology group, which are not
separately tracked, as well as certain hardware and software upgrades and
training costs. If we or key third parties such as suppliers and customers are
not Y2K ready, there could be an adverse effect on our business, results of
operations and financial condition. We believe that with the implementation of
the Y2K program the risk of significant interruptions of normal operations is
reduced. We have developed certain contingency plan to address a situation in
which Y2K problems do cause an interruption in normal business activities.

                                       12
<PAGE>

                                USE OF PROCEEDS

     We plan to use the net proceeds from the sale of the Common Stock for
general corporate purposes, including working capital, capital expenditures and
acquisitions.  Each time we sell the Securities, we will provide a Prospectus
Supplement that will contain information about how we intend to use the net
proceeds from the Securities.

                              PLAN OF DISTRIBUTION

     We may offer the Securities directly to purchasers, to or through
underwriters, through dealers or agents, or through a combination of such
methods.

     If underwriters are used in an offering of the Securities, we will execute
an underwriting agreement with such underwriters and will set out the name of
each underwriter and the terms of the transaction (including any underwriting
discounts and other terms constituting compensation of the underwriters and any
dealers) in a Prospectus Supplement.  If an underwriting syndicate is used, the
managing underwriter(s) will be set forth on the cover of a Prospectus
Supplement.  Common Stock will be acquired by the underwriters for their own
accounts and may be resold from time to time in one or more transactions,
including negotiated transactions, at a fixed public offering price or at
varying prices determined at the time of sale.  Any public offering price and
any discounts or concessions allowed or reallowed or paid to dealers may be
changed from time to time.

     If dealers are used in an offering of the Securities, we will sell the
Securities to the dealers as principals.  The dealers then may resell such
shares of Common Stock to the public at varying prices which they determine at
the time of resale.  The names of the dealers and the terms of the transaction
will be set forth in a Prospectus Supplement.

     If agents are used in an offering of the Securities, the names of the
agents and the terms of the agency will be set forth in a Prospectus supplement.
Unless otherwise indicated in a Prospectus Supplement, the agents will act on a
best-efforts basis for the period of their appointment.

     Dealers and agents named in a Prospectus Supplement may be deemed to be
underwriters (within the meaning of the Securities Act of 1933) of the
Securities described therein.  Underwriters, dealers and agents, may be entitled
to indemnification by us against certain liabilities (including liabilities
under the Securities Act of 1933) under underwriting or other agreements.  The
terms of any indemnification provisions will be set forth in a Prospectus
Supplement.

     We may solicit offers to purchase the Securities from, and sell the
Securities directly to, institutional investors or others who may be deemed to
be underwriters within the meaning of the Securities Act of 1933 with respect to
any resales thereof.  The terms of any offer will be set forth in a Prospectus
Supplement.

     Certain underwriters, dealers or agents and their associates may engage in
transactions with, and perform services for us in the ordinary course of
business, including refinancing of our indebtedness.

     If so indicated in a Prospectus Supplement, we will authorize underwriters
or other persons acting as our agents to solicit offers by institutional
investors to purchase our Common Stock pursuant to contracts providing for
payment and delivery on a future date.  We may enter contracts with commercial
and savings banks, insurance companies, pension funds, investment companies,
educational and charitable institutions and other institutional investors.  The
obligations of any institutional investor will be subject to the condition that
its purchase of our

                                       13
<PAGE>

Common Stock will not be illegal, at the time of delivery. The underwriters and
other agents will not be responsible for the validity or performance of
contracts.

     To facilitate an offering of a series of the Securities, certain persons
participating in the offering may engage in transactions that stabilize,
maintain or otherwise affect the price of our Common Stock.  This may include
over-allotments of the Securities.  Over-allotments involve the sale by persons
participating in the offering of more Common Stock than we have sold to them.
In such circumstances, these persons would cover over-allotments by purchasing
our Common Stock in the open market or by exercising their over-allotment
options.  In addition, such persons may stabilize or maintain the price of our
Common Stock by bidding for or purchasing our Common Stock in the open market or
by imposing penalty bids, whereby selling concessions allowed to dealers
participating in any such offering may be reclaimed if the Securities they sell
is repurchased in connection with stabilization transactions.  The effect of
these transactions may be to stabilize or maintain the market price of our
Common Stock at a level above that which might otherwise prevail in the open
market.  These transactions, if commenced, may discontinue at any time.

                           DESCRIPTION OF SECURITIES

AUTHORIZED AND OUTSTANDING CAPITAL STOCK

     Pursuant to our Certificate of Incorporation, as amended, we are authorized
to issue up to 80,000,000 shares of our common stock, $.01 par value per share.
We are authorized to issue up to 1,000,000 shares of preferred stock, $1.00 par
value per share.

     As of December 20, 1999, there were issued and outstanding 30,689,019
shares of our common stock (excluding 85,000 treasury shares). The table below
sets forth for each of our stock option plans, as of December 20, 1999, (a) the
number of shares of common stock reserved for issuance under each option plan
and (b) of the shares of common stock reserved for issuance, (1) the number of
shares issued pursuant to the exercise of granted options, (2) the number of
shares still available for issuance and (3) the number of shares available for
issuance or no longer available for issuance.

<TABLE>
<CAPTION>
                                            Shares         Subject to       Issued                           No Longer
                                           Reserved       Outstanding     Pursuant to     Available for    Available for
                                              For            Option        Exercised         Future            Future
                                           Issuance          Grants         Options         Issuance          Issuance
                                        ---------------  --------------  -------------  -----------------  --------------
<S>                                     <C>              <C>             <C>            <C>                <C>
1986 Stock Option Plan                        4,882,812       2,290,392      2,353,073              -             239,347
1995 Stock Option Plan                        5,000,000       3,359,151        161,189      1,479,660                   -
1991 Directors' Stock Option Plan               244,141          73,246         36,623              -             134,272
1994 Directors' Stock Option Plan               488,281         277,546         46,388        164,347                   -
1999 Non-Qualified Stock Option Plan          1,000,000         450,000              -        550,000                   -
Officer Stock Option Agreement                  732,423         732,423              -              -                   -
</TABLE>

     In addition, 366,211 shares of our common stock are reserved for issuance
under our 1991 Employee Stock Purchase Plan (51,597 of which have been issued
and 314,614 of which are still available for future issuance).

     In addition, 1,800,000 shares have been reserved for issuance upon
conversion of the Series C Preferred Stock and exercise of the Warrants issued
in a private placement of our securities in March 1998 and 50,000 shares have
been reserved for issuance upon the exercise of warrants issued to Reedland
Capital Partners. Pursuant to our issuance of convertible notes and warrants in
March 1999, an additional 2,046,333 shares of our common stock have been
reserved for issuance upon (i) the conversion of convertible notes into common
stock, (ii) the payment of accrued interest on the convertible notes in common
stock, and (iii) the exercise of warrants issued in the financing.

                                       14
<PAGE>

Pursuant to an asset purchase transaction with Baxter Healthcare Corporation, an
additional 50,000 shares of our common stock have been reserved for issuance and
were issued as of April 30, 1999.

COMMON STOCK

     The holders of Common Stock are entitled to one vote per share for each
share held of record on all matters submitted to a vote of stockholders and are
entitled to receive ratably such dividends as may be declared by the Board of
Directors out of funds legally available therefor. In the event of a
liquidation, dissolution or winding up of the company, holders of Common Stock
have the right to a ratable portion of assets remaining after payment of
liabilities and the liquidation preferences of any outstanding Preferred Stock.
The holders of Common Stock have no preemptive rights or rights to convert their
Common Stock into any other securities and are not subject to future calls or
assessments by the company.  All outstanding shares of Common Stock are fully
paid and non-assessable.


PREFERRED STOCK

     The Board of Directors may, without further action of our stockholders,
issue preferred stock in one or more series and fix the rights and preferences
thereof, including dividend rights, dividend rates, conversion rights, voting
rights, terms of redemption (including sinking fund provisions), redemption
price or prices, liquidation preferences and the number of shares constituting
any series or the designation of such series.

     We have authorized 1,000,000 shares of preferred stock at August 10, 1999,
of which 250,000 shares are designated as Series A convertible preferred stock,
50,000 shares are designated as Series B junior participating preferred stock
and 200 shares are designated as Series C convertible preferred stock. The
250,000 shares of Series A convertible preferred stock that were previously
issued were subsequently converted into 312,500 shares of common stock in
October 1995.   No shares of Series A or Series B  preferred stock are issued
and outstanding as of the date of this prospectus or were issued and outstanding
as of December 31, 1996, 1997 or 1998.

     In March 1998, we completed a placement of 200 shares of Series C
convertible preferred stock and warrant financing with two institutional
investors. The Series C preferred stock pay no dividends, have no voting rights,
and are convertible into common stock on a scheduled basis over two years based
on market price at time of conversion. The conversion price per share is to be
the lower of (a) $28.80 and (b) the average of the closing bid prices of our
common stock for any three trading days selected by the investors during the 20
consecutive trading days immediately prior to the date of conversion, in each
case, subject to adjustment for subsequent dilutive financings or if we declare
a dividend or make a distribution in shares of common stock, subdivide or
reclassify the outstanding shares of common stock into a greater number of
shares, or combine or reclassify our outstanding common stock into a smaller
number of shares. The investors, in the aggregate, may not convert preferred
stock into common stock in excess of 1,136,364 shares. However, no limits exist
for conversions upon redemption or upon a major transaction, such as a
consolidation or merger, the sale or transfer of substantially all of our
assets, or a purchase, tender or exchange offer for more than 50% of our
outstanding shares of common stock that is accepted by the holders of common
stock.  In addition, the investors are not entitled to convert Series C
preferred stock in excess of that number of Series C preferred stock shares
that, upon giving effect to the conversion, would cause the aggregate number of
shares of common stock beneficially owned by that investor and its affiliates to
exceed 4.9% of our outstanding shares of common stock following the conversion.
We may call for conversion of all or part of the shares of Series C preferred
stock under certain conditions based on continued improvement in the price of
our common stock. If any Series C preferred stock remains outstanding on the
mandatory conversion date of March 26, 2000, we have the option of redeeming any
such outstanding Series C preferred stock by: (1) paying cash equal to the
product of the number of Series C preferred stock outstanding multiplied by the
stated value of $100,000 per share; (2) issuing common stock equal to 1.15 of
the stated value divided by the average of the closing bid prices for the 20
consecutive trading days prior to the mandatory conversion date; or (3) any
combination of these methods. In addition, the investors received three-year
warrants to purchase an aggregate of 200,000 shares of common stock at

                                       15
<PAGE>

$31.20 per share. The warrants may be exercised at any time prior to April 2001.
In July 1998, the investors exercised their right to receive additional warrants
to purchase 150,000 shares of common stock at $17.45 per share with an
expiration date of March 26, 2001. We also issued a warrant to purchase an
aggregate of 50,000 shares of common stock at $28.80 per share to the placement
agent that expires March 25, 2001. No further warrants may be issued under the
Series C preferred stock placement.

     In April 1998, we filed a registration statement for 1,800,000 shares of
common stock, the maximum number of shares that may be acquired relating to this
transaction; except for mandatory conversion where the common share limit does
not apply. All shares have been reserved for issuance. The SEC declared this
registration statement effective in May 1998. In May, September and November
1998, an aggregate of $13,800,000 face amount of the Series C preferred stock
was converted into common stock resulting in the issuance of approximately
1,136,000 shares of common stock.   As of the date of this prospectus,  we have
62 shares of Series C convertible preferred stock outstanding.

     In the event of any liquidation, dissolution or winding up of the company,
the holders of the Series C preferred stock will be entitled to receive an
amount per Series C preferred stock share equal to the stated value, before any
amount shall be paid to the holders of any of our capital stock of any class
junior in rank to the Series C preferred stock. As long as the initially issued
shares of Series C preferred stock remain outstanding, then without the prior
express written consent of the holders of not less than two-thirds (2/3) of the
then outstanding Series C preferred stock, we may not authorize or issue
additional or other capital stock that is of senior rank to the Series C
preferred stock in respect of the preferences as to distributions and payments
upon the liquidation, dissolution and winding up of the company.  Until all of
the Series C preferred stock has been converted or redeemed, we may not redeem
or declare or pay any cash dividend or distribution on our common stock or any
other series of our preferred stock without the prior express written consent of
the holders of not less than two-thirds (2/3) of the then outstanding Series C
preferred stock.

     Additional shares of authorized preferred stock may be issued without
stockholder approval, subject to the rights of any holders of outstanding Series
C preferred stock.  The Board of Directors is authorized to issue such shares in
one or more series and to fix the rights, preferences, privileges,
qualifications, limitations and restrictions thereof, including dividend rights
and rates, conversion rights, voting rights, terms of redemption, redemption
prices, liquidation preferences and the  number of shares constituting any
series or the designation of such series, without any vote or action by the
holders of common stock.  Any preferred stock to be issued could rank prior to
the common stock with respect to dividend rights and rights on liquidation.  The
Board of Directors, without approval of the holders of common stock, may issue
preferred stock with voting and conversion rights that could adversely affect
the voting power of holders of common stock or create impediments to persons
seeking to gain control of the company.

     The rights of the holders of common stock as described above will be
subject to, and may be adversely affected by, the rights of holders of the
Series C preferred stock and any preferred stock that may be issued in the
future. Issuance of preferred stock, while providing desirable flexibility in
connection with possible acquisitions, and other corporate purposes, could have
the effect of making it more difficult for a third party to acquire, or of
discouraging a third party from acquiring, a majority of our outstanding voting
stock.  See "Description of Securities"-- Shareholder Rights."

TREASURY STOCK

     In September 1998, the Board of Directors authorized a common stock
repurchase program.  Repurchases are allowed through open-market transactions
for up to 500,000 shares that will provide us with treasury shares for general
corporate purposes. At December 20, 1999, we had in treasury  85,000 shares of
common stock for an aggregate purchase price of $804,000. The stock repurchase
program may be discontinued at any time.

                                       16
<PAGE>

SHAREHOLDER RIGHTS

     In August 1995, the Board of Directors adopted a Stockholder Rights Plan
and declared a dividend of one right for each outstanding share of common stock
to stockholders of record on September 1, 1995.  After adjusting for two one-
for-four stock dividends distributed during 1997 and one one-for-four stock
dividend distributed during 1998, there is approximately .51 of a right for each
outstanding share of common stock.  Each right only becomes exercisable and
transferable apart from the common stock at the earlier of: (1) ten days after a
person or group acquires beneficial ownership of 15% or more of outstanding
common stock; or (2) ten business days following an announcement of a tender or
exchange offer of 30% or more of outstanding stock.

     Initially, each right, upon becoming exercisable, would entitle the holder
to purchase one-thousandth of a share of Series B Junior participating preferred
stock at an exercise price of $85, subject to adjustment.  If a person or group
acquires beneficial ownership of 15% or more of the outstanding shares of common
stock, then each holder of a right (other than rights held by the acquiring
person or group) would have the right to receive that number of shares of common
stock which equals the exercise price of the right divided by one-half of the
current market price of the common stock.

     The rights may be redeemed for $0.01 per right at any time until the tenth
day following the stock acquisition date.  The rights will expire on September
1, 2005.

CONVERTIBLE DEBT

     On March 31, 1999, we completed a financing of $20,000,000 through the
private placement of five year convertible debentures and 400,000 warrants to
purchase common stock.  The debentures are convertible at a fixed price of
$14.50 per share any time on or after March 30, 2000. Interest on the debentures
accrues at 7% annually, payable in cash, common stock (at the average trading
price for the twenty trading days preceding the due date) or any combination
thereof, at our option, semi-annually on September 30 and March 31 or on the
date any of the principal outstanding under the notes has been converted into
common stock. At our option, at any time on or after March 30, 2002, the
debentures may be prepaid by conversion of the principal into common stock at
the conversion price of $14.50, cash or any combination thereof and payment of
any accrued interest as described above, provided that the average per share
market value for the twenty consecutive trading days immediately preceding the
date of prepayment equals or exceeds $38.67 per share. The debentures mature on
March 29, 2004 and are payable in cash upon maturity.

WARRANTS

     In connection with our issuance of $20 million of 7% convertible debt in
March 1999, each purchaser of the convertible debt received one warrant for each
$50.00 in face value of the convertible debt purchased, for an aggregate
issuance of 400,000 warrants. Each warrant grants the right to purchase one
share of common stock at an exercise price of $21.75 at any time on or before
March 29, 2004. The warrants are exercisable upon 75 days' prior written notice
by the registered holder of the warrant, except upon certain conditions. The
exercise price and the number of shares of common stock issuable upon exercise
of each warrant are subject to adjustment from time to time upon any stock
dividend or other distribution upon shares of capital stock, stock split,
subdivision, combination or reclassification of the outstanding shares of
common stock and consolidation, merger or transfer of all or substantially all
of our assets.

                          TRANSFER AGENT AND REGISTRAR

     The transfer agent and registrar for our common stock is American Stock
Transfer & Trust Company.

                     LEGALITY OF COMMON STOCK AND WARRANTS

                                       17
<PAGE>

     The validity of the securities offered in this prospectus is being passed
upon for us by Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston,
Massachusetts.

                                    EXPERTS

     The financial statements incorporated in this prospectus by reference to
our Annual Report on Form 10-K for the fiscal year ended December 31, 1998 have
been so incorporated in reliance on the report of PricewaterhouseCoopers LLP,
independent accountants, given on the authority of said firm as experts in
auditing and accounting.

                                INDEMNIFICATION

     Section 145 of the General Corporation Law of the State of Delaware
provides that we have the power to indemnify our directors, officers, employees
or agents and certain other persons serving at our request in related capacities
against amounts paid and expenses incurred in connection with an action or
proceeding to which he or she is or is threatened to be made a party by reason
of such position, if such person shall have acted in good faith and in a manner
he reasonably believed to be in or not opposed to our best interests, and, in
any criminal proceeding, if such person had no reasonable cause to believe his
conduct was unlawful, provided that, in the case of actions brought by or on
behalf of us, no indemnification shall be made with respect to any matter as to
which such person shall have been adjudged to be liable to us unless and only to
the extent that the adjudicating court determines that such indemnification is
proper under the circumstances.

     Section 102(b)(7) of the Delaware General Corporation Law permits us to
provide in our certificate of incorporation that our directors shall not be
personally liable to us or our stockholders for monetary damages for breach of
fiduciary duty as a director, except for liability (i) for any breach of the
director's duty of loyalty to the corporation or its stockholders, (ii) for acts
or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the Delaware General
Corporation Law, or (iv) for any transaction from which the director derived an
improper personal benefit.

     Our Restated Certificate of Incorporation provides for indemnification to
the fullest extent permitted by law and that we may advance litigation expenses
to an officer or director prior to the final disposition of an action.

     Our Restated Certificate of Incorporation also provides, as permitted by
Delaware law, that directors shall not be personally liable to us or our
stockholders for monetary damages for breach of fiduciary duty as a director,
except for liability (i) for any breach of a director's duty of loyalty to the
company or its stockholders, (ii) for acts or omissions not in good faith or
which involve intentional misconduct or knowing violations of law, (iii) under
Section 174 of the Delaware General Corporation Law or (iv) for any transaction
from which the director derived an improper personal benefit.

     We have a Directors and Officers liability insurance policy that insures
our officers and directors against certain liabilities.

Commission Policy

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers or persons controlling us, we have been
informed that in the opinion of the SEC such indemnification is against public
policy as expressed in the Securities Act and is therefore unenforceable.

                                       18
<PAGE>

You should rely only on the information contained in this prospectus. We have
not authorized anyone to provide you with information different from that
contained in this prospectus. We are offering to sell and seeking offers to buy
our Securities only in jurisdictions where offers and sales are permitted. The
information contained in this prospectus is accurate only as of August __, 1999.
You should not assume that this prospectus is accurate as of any other date.

$50,000,000 ORGANOGENESIS INC. Debt Securities Preferred Stock Common Stock (We
will not issue in excess of 3,000,000 shares of our common stock, either
directly or upon conversion of any convertible securities, sold pursuant to this
Prospectus)


<TABLE>
<CAPTION>
                              TABLE OF CONTENTS
                                                           Page
                                                           ----
<S>                                                        <C>
Available Information.....................................
Incorporation of Certain Information
 by Reference.............................................
The Company...............................................
Risk Factors..............................................
Use of Proceeds...........................................
Plan of Distribution......................................
Description of Securities.................................
Transfer Agent and Registrar..............................
Legality of Common Stock and Warrants.....................
Experts...................................................
Indemnification...........................................
</TABLE>

                            --------------------
                                  PROSPECTUS
                            --------------------

December  __, 1999


<PAGE>

                PART II.  INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14.  OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

      The table sets forth our estimates (other than the SEC and AMEX Filing
Fees) of our expenses in connection with the issuance and distribution of the
Securities being registered. Other than the SEC registration fee, the amounts
stated are estimates.

<TABLE>
<CAPTION>
Item                                                                                             Amount
----                                                                                             ------
<S>                                                                                           <C>
 SEC registration fee.......................................................................   $ 13,200.00
 AMEX listing fee...........................................................................     17,500.00
 Legal fees and expenses....................................................................     25,000.00
 Accounting fees and expenses...............................................................     10,000.00
 Miscellaneous fees and expenses............................................................   $ 10,000.00
                                                                                               -----------
 Total......................................................................................   $ 75,700.00
                                                                                               -----------
 </TABLE>

ITEM 15.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

  See "Indemnification" contained in Part I hereof, which is incorporated herein
by reference.

  We shall indemnify and hold harmless persons who serve at our express written
request as directors or officers of another organization in which we own shares
or of which we are a creditor.

  In addition, the Registration Rights Agreements, filed as Exhibit 99c and 99d
hereto, contain provisions for indemnification by the parties to those
agreements and their officers, directors, and controlling persons against
certain liabilities under the Securities Act of 1933.

ITEM 16.  EXHIBITS.

EXHIBIT
NUMBER        DESCRIPTION
------      ------------------------------------------------------------------

 4.1      The Restated Certificate of Incorporation of the Registrant
          (previously filed with the Commission on August 16, 1999 as Exhibit
          3(I) to the Registrant's Form 10-Q for the quarter ended June 30,
          1999, and incorporated herein by reference).

 4.2      Form of Common Stock Certificate (previously filed as Exhibit No. 4c
          to the Registrant's Registration Statement on Form S-1, File No. 33-
          48340, and incorporated herein by reference).

 5        Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., with
          respect to the legality of the securities being registered.

23.1      Consent of PricewaterhouseCoopers LLP.

23.2      Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
          (included in Exhibit 5).

24        Power of Attorney (filed in Part II of this Registration Statement).
<PAGE>

ITEM 17.  UNDERTAKINGS.

A.   Rule 415 Offering

     The undersigned registrant hereby undertakes:

     (1)  To file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:

     (i)  To include any prospectus required by Section 10(a)(3) of the
Securities Act;

     (ii) To reflect in the prospectus any facts or events arising after the
effective date of the registration statement (or the most recent post-effective
amendment thereof) which, individually or in the aggregate, represent a
fundamental change in the information set forth in the registration statement.
Notwithstanding the foregoing, any increase or decrease in volume of securities
offered (if the total dollar value of securities offered would not exceed that
which was registered) and any deviation from the low or high end of the
estimated maximum offering range may be reflected in the form of prospectus
filed with the Commission pursuant to Rule 424(b)(sec.230.424(b) of this
chapter) if, in the aggregate, the changes in volume and price represent no more
than a 20% change in the maximum aggregate offering price set forth in the
"Calculation of Registration Fee" table in the effective registration statement.

     (iii)To include any material information with respect to the plan of
distribution not previously disclosed in the registration statement or any
material change to such information in the registration statement;

Provided, however, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the
registration statement is on Form S-3 or Form S-8, and the information required
to be included in a post-effective amendment by those paragraphs is contained in
periodic reports filed by the Registrant pursuant to Section 13 or Section 15(d)
of the 1934 Act that are incorporated by reference in the registration
statement.

     (2)  That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     (3)  To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.

B.   Filings Incorporating Subsequent Exchange Act Documents by Reference

     The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to section 13(a) or section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

C.   Incorporated Annual and Quarterly Reports.

     The undersigned registrant hereby undertakes to deliver or cause to be
delivered with the prospectus, to each person to whom the prospectus is sent or
given, the latest annual report to security holders that is incorporated by
reference in the prospectus and furnished pursuant to and meeting the
requirements of Rule 14a-3 or Rule 14c-3 under the Securities Exchange Act of
1934; and, where interim financial information required to be presented by
Article 3 of Regulation S-X is not set forth in the prospectus, to deliver, or
cause to be delivered to each person to whom the prospectus is sent or given,
the latest quarterly report that is specifically incorporated by reference in
the prospectus to provide such interim financial information.
<PAGE>

D.   Request for Acceleration of Effective Date or Filing of Registration
Statement on Form S-8

     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933 and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.
<PAGE>

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Amendment No. 1 to
this registration statement on Form S-3 to be signed on its behalf by the
undersigned, thereunto duly authorized, in the Town of Canton, Commonwealth of
Massachusetts, on December 23, 1999.

                              ORGANOGENESIS INC.

                              By: /s/ Herbert M. Stein
                                 -----------------------------------------
                                 Herbert M. Stein, Chief Executive Officer

                               POWER OF ATTORNEY
                               -----------------

     KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Philip M. Laughlin and Donna Abelli Lopolito, or
any of them, his attorney-in-fact, each with the power of substitution, for him
in any and all capacities, to sign any and all amendments (including post-
effective amendments) to this registration statement, (or any other registration
statement for the same offering that is to be effective upon filing pursuant to
Rule 462(b) under the Securities Act) and to file the same, with all exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, hereby granting unto said attorneys-in-fact and agents, and
each of them, full power and authority to do and perform each and every act and
thing requisite or necessary to be done in and about the premises, as full to
all intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents or any of them or their or
his substitutes may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
SIGNATURE                                            TITLE                       DATE
<S>                                    <C>                                 <C>

/s/ Herbert M. Stein                   Chief Executive Officer             December 23, 1999
--------------------------
Herbert M. Stein                       and Chairman of the Board
                                       (principal executive officer)

/s/ Philip M. Laughlin                 President, Chief Operating          December 23, 1999
--------------------------
Philip M. Laughlin                     Officer and Director


/s/ Donna Abelli Lopolito              Vice President,                     December 23, 1999
--------------------------
Donna Abelli Lopolito                  Chief Financial Officer,
                                       Treasurer  and Secretary
                                       (principal financial officer
                                       and principal  accounting officer)

/s/ Richard S. Cresse                  Director                            December 23, 1999
--------------------------
Richard S. Cresse

/s/ Albert Erani                       Director                            December 23, 1999
--------------------------
Albert Erani

/s/ David A. Gardner                   Director                            December 23, 1999
--------------------------
David A. Gardner

/s/ Bernard  A. Marden                 Director                            December 23, 1999
--------------------------
</TABLE>
<PAGE>

<TABLE>
<S>                                   <C>                                  <C>
Bernard A. Marden

/s/ Bjorn R. Olsen                     Director                            December 23, 1999
--------------------------
Bjorn R. Olsen

/s/ Marguerite A. Piret                Director                            December 23, 1999
--------------------------
Marguerite A. Piret

/s/ Anton E. Schrafl                   Director                            December 23, 1999
--------------------------
Anton E. Schrafl
</TABLE>
<PAGE>

                               ORGANOGENESIS INC.

                          INDEX TO EXHIBITS FILED WITH
                        FORM S-3 REGISTRATION STATEMENT

EXHIBIT
NUMBER        DESCRIPTION
------   ----------------------------------------------------------------------

4.1       The Restated Certificate of Incorporation of the Registrant
          (previously filed with the Commission on August 16, 1999 as Exhibit
          3(I) to the Registrant's Form 10-Q for the quarter ended June 30,
          1999, and incorporated herein by reference).

4.2       Form of Common Stock Certificate (previously filed as Exhibit No. 4c
          to the Registrant's Registration Statement on Form S-1, File No. 33-
          48340, and incorporated herein by reference).

5         Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., with
          respect to the legality of the securities being registered.

23.1      Consent of PricewaterhouseCoopers LLP.

23.2      Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
          (included in Exhibit 5)

24        Power of Attorney (filed in Part II of this Registration Statement).