<PAGE>

                                                                     Exhibit 3.1

                      RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                        PREMIER RESEARCH WORLDWIDE, LTD.

         Premier Research Worldwide, Ltd., a corporation organized and existing
under the laws of the State of Delaware, hereby certifies as follows:

         FIRST: that (i) the name of the corporation is PREMIER RESEARCH
WORLDWIDE, LTD., formerly known as Research Data Worldwide, Ltd. which was
formerly known as Research Data Corporation, which is the name under which the
corporation was originally incorporated, and (ii) the date of filing its
original Certificate of Incorporation with the Secretary of State was August 19,
1993.

         SECOND: that this Restated Certificate of Incorporation was duly
adopted by the Corporation's stockholders in accordance with the provisions of
Section 245 of the General Corporation Law of Delaware.

         THIRD: that the text of the Certificate of Incorporation is hereby
amended to read in its entirety as follows:


                                    ARTICLE I

         The name of the Corporation is PREMIER RESEARCH WORLDWIDE, LTD.


                                   ARTICLE II

         The address of the registered office of the Corporation in the State of
Delaware is 1209 Orange Street, in the City of Wilmington, County of New Castle.
The name of the Corporation's registered agent at such registered office is The
Corporation Trust Company.


                                   ARTICLE III

         The purpose of the Corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of Delaware.



                                   ARTICLE IV

         The aggregate number of shares which the corporation shall have
authority to issue is 15,500,000, by classes and par value of shares as follows:

                                                  Par Value
                Class          No. of Shares      Per Share
                -----          -------------      ---------
                Common          15,000,000         $ 0.01
                Preferred          500,000         $10.00






<PAGE>

The relative rights, preferences and limitations of the shares of each class are
as follows:

         Preferred. The Board of Directors is authorized to adopt by resolution
at any time, or from time to time, amendments to the Certificate of
Incorporation in respect of any unissued and/or treasury shares of preferred
stock, and thereby to fix or change the division of shares of the preferred
stock into classes and/or into series within any class or classes, and the
determination of the relative rights, preferences and limitations of the shares
of any class or series. The authority of the Board with respect to each class or
series of preferred stock shall include, but not be limited to, determination of
the following:

         (a) The number of shares constituting that class or series and the
distinctive designation of that class or series;

         (b) The dividend rate on the shares of that class or series, whether
dividends shall be cumulative, and, if so, from which date or dates;

         (c) Whether that class or series shall have voting rights, in addition
to any voting rights provided by law, and, if so, the terms of such voting
rights;

         (d) Whether that class or series shall have conversion privileges and,
if so, the terms and conditions of such conversion, including provision for
adjustment of the conversion rate in such events as the Board of Directors shall
determine;

         (e) Whether or not the shares of that class or series shall be
redeemable, and, if so, the terms and conditions of such redemption, including
the date or dates upon or after which they shall be redeemable, and the amount
per share payable in case of redemption, which amount may vary under different
conditions;

         (f) The rights of the shares of that class or series in the event of
voluntary or involuntary liquidation, dissolution or winding up of the
Corporation; and

         (g) Any other relative rights, preferences and limitations of that
class or series as may be permitted or required by law.

         Common. Each share of common stock shall be entitled to one vote on all
matters submitted to a vote of stockholders. The common stockholders shall be
entitled to such dividends as may be declared by the Board of Directors from
time to time, provided that required dividends, if any, on the preferred stock
have been paid or provided for. In the event of the liquidation, dissolution, or
winding up, whether voluntary or involuntary, of the Corporation, the assets and
funds of the Corporation available for distribution to stockholders, and
remaining after the payment to holders of preferred stock of the amounts to
which they are entitled, shall be divided and paid to the holders of the common
stock according to their respective shares.

                                    ARTICLE V

         (a) The number of directors which shall constitute the whole Board of
Directors shall be not less than two nor more than fifteen. The exact number of
directors within such maximum and minimum shall be determined by resolution duly
adopted by the Board of Directors by a majority vote of the whole Board.






<PAGE>

         (b) The Board of Directors shall be divided into three classes, as
nearly equal in number as the then total number of directors constituting the
whole Board permits. At the meeting of stockholders, or by written consent in
lieu of such meeting, at or by which this Restated Certificate of Incorporation
is adopted, directors of the first class shall be elected to hold office for a
term expiring at the next ensuing annual meeting, directors of the second class
shall be elected to hold office for a term expiring at the second ensuing annual
meeting, and directors of the third class shall be elected to hold office for a
term expiring at the third ensuing annual meeting. At each annual meeting of
stockholders following such initial classification and election, directors in
numbers equal to the number of the class whose terms expire at the time of such
meeting shall he elected to hold office until the second succeeding annual
meeting of stockholders. Each director shall hold office until his successor is
elected and qualified, or until his earlier resignation or removal.

         (c) Newly created directorships resulting from any increase in the
authorized number of directors and any vacancies in the Board of Directors
resulting from death, resignation, retirement, disqualification, removal from
office or other cause may be filled only by a majority vote of the whole Board,
and directors so chosen shall hold office for a term expiring at the annual
meeting of stockholders at which the term of the class to which they have been
elected expires.

         (d) Any directors elected pursuant to any special voting rights of one
or more series of preferred stock shall be excluded from, and for no purpose be
counted in, the scope and operation of the foregoing provisions of this Article
V.

         (e) Notwithstanding any other provisions of this Certificate of
Incorporation or the Bylaws of the Corporation (and notwithstanding the fact
that some lesser percentage may be specified by law, this certificate of
incorporation or the by-laws of the Corporation), the affirmative vote of the
holders of seventy percent (70%) or more of the outstanding shares of capital
stock of the Corporation entitled to vote generally in the election of directors
(considered for this purpose as one class) shall he required to amend, alter,
change or repeal this Article V.



                                   ARTICLE VI

         1. (A) In addition to any affirmative vote required by law or this
Certificate of Incorporation, and except as otherwise expressly provided in
paragraph 2 of this Article VI:

                (i) any merger or consolidation of the Corporation or any
Subsidiary (as hereinafter defined) with (a) any Interested Stockholder (as
hereinafter defined) or (b) any other corporation (whether or not itself an
Interested Stockholder) which is, or after such merger or consolidation would
be, an Affiliate (as hereinafter defined) of an Interested Stockholder; or

                (ii) any sale, lease, exchange, mortgage, pledge, transfer or
other disposition (in one transaction or a series of transactions), to or with
any Interested Stockholder or any Affiliate of any Interested Stockholder, of
any assets of the Corporation or any Subsidiary having an aggregate Fair Market
Value (as hereinafter defined) of $1,000,000 or more; or






<PAGE>

                (iii) the issuance or transfer by the Corporation or any
Subsidiary (in one transaction or a series of transactions) of any securities of
the Corporation or any Subsidiary to any Interested Stockholder or any Affiliate
of any Interested Stockholder in exchange for cash, securities or other property
(or a combination thereof) having an aggregate Fair Market Value of $1,000,000
or more; or

                (iv) the adoption of any plan or proposal for the liquidation or
dissolution of the Corporation proposed by or on behalf of an Interested
Stockholder or any Affiliate of any Interested Stockholder; or

                (v) any reclassification of securities (including any reverse
stock split), or recapitalization of the Corporation, or any merger or
consolidation of the Corporation with any of its Subsidiaries or any other
transaction (whether or not with or into or otherwise involving an Interested
Stockholder) which has the effect, directly or indirectly, of increasing the
proportionate share of the outstanding shares of any class of equity or
convertible securities of the Corporation or any Subsidiary which is directly or
indirectly owned by any Interested Stockholder or any Affiliate of any
Interested Stockholder; shall require the affirmative vote of the holders of at
least eighty percent (80%) of the then outstanding shares of each class of the
capital stock of the Corporation (the "Voting Stock"). Such affirmative vote
shall be required notwithstanding the fact that no vote may be required, or that
a lesser percentage may be specified, by law or in any agreement with any
national securities exchange or otherwise. Notwithstanding any other provision
of this certificate of incorporation to the contrary, for purposes of this
Article VI, each share of the Voting Stock shall have one vote.

            (B) The term "Business Combination" as used in this Article VI shall
mean any transaction which is referred to in any one or more of clauses (i)
through (v) of sub-paragraph (A) of this paragraph 1.

         2. The provisions of paragraph 1 of this Article VI shall not be
applicable to any particular Business Combination, and such Business Combination
shall require only such affirmative vote as is required by law and any other
provision of this certificate of incorporation, if all of the conditions
specified in either of the following sub-paragraphs (A) and (B) are met:

            (A) The Business Combination shall have been approved by a majority
of the Continuing Directors (as hereinafter defined); provided, however, that
such approval shall only be effective if obtained at a meeting at which a
Continuing Director Quorum (as hereinafter defined) is present.

            (B) All of the following conditions shall have been met:

                (i) The aggregate amount of (x) cash and (y) Fair Market Value
as of the date of the consummation of the Business Combination of consideration
other than cash, to be received per share by holders of each class of the
Corporation's capital stock in such Business Combination shall be at least equal
to the highest amount determined under sub-clauses (a), (b) and (c) below:

                    (a) (if applicable) the highest per share price (including
any brokerage commissions, transfer taxes and soliciting dealers' fees) paid by
the Interested Stockholder for any share of such class acquired by it (1) within
the two-year period immediately prior to the first public announcement of the
proposal of the Business Combination (the "Announcement Date") or (2) in the
transaction in which it became an Interested Stockholder, whichever is higher;

                    (b) the Fair Market Value per Share of such class on the
Announcement Date or on the date on which the Interested Stockholder became an
Interested Stockholder (such latter date is referred to in this Article VI as
the "Determination Date"), whichever is higher; and






<PAGE>

                    (c) (if applicable) the highest preferential amount per
share to which the holders of shares of such class would be entitled in the
event of any voluntary or involuntary liquidation, dissolution or winding up of
the affairs of the Corporation, regardless of whether the Business Combination
to be consummated constitutes such an event.

                (ii) The consideration to be received by holders of a particular
class of outstanding Voting Stock shall be in cash or in the same form as the
Interested Stockholder has previously paid for shares of such class of Voting
Stock. If the Interested Stockholder has paid for shares of any class of Voting
Stock with varying forms of consideration, the form of consideration for such
class of Voting Stock shall be either cash or the form used to acquire the
largest number of shares of such class of Voting Stock previously acquired by
it. If the Interested Shareholder shall not have previously acquired shares of a
particular class, the form of consideration to be received by holders of such
class shall be cash.

                (iii) After such Interested Stockholder has become an Interested
Stockholder, such Interested Stockholder shall not have received the benefit,
directly (except proportionately as a stockholder), of any loans, advances,
guarantees, pledges or other financial assistance or any tax credits or other
tax advantages provided by the Corporation, whether in anticipation of or in
connection with such Business Combination or otherwise.

                (iv) A proxy or information statement describing the proposed
Business Combination and complying with the requirements of the Securities
Exchange Act of 1934 and the rules and regulations thereunder (or any subsequent
provisions replacing such Act, rules or regulations) shall be mailed to public
stockholders of the Corporation at least 30 days prior to the consummation of
such Business Combination (whether or not such proxy or information statement is
required to be mailed pursuant to such Act or subsequent provisions).

         3. For the purposes of this Article VI:

            (A) The term "Person" shall mean any individual, firm, corporation
or other entity.

            (B) The term "Interested Stockholder" shall mean any person (other
than the Corporation or any Subsidiary and other than any profit-sharing,
employee stock ownership or other employee benefit plan of the Corporation or
any Subsidiary or any trustee of or fiduciary with respect to any such plan when
acting in such capacity) who or which:

                (i) is the beneficial owner (as hereinafter defined) of more
than twenty percent (20%) of the Voting Stock; or

                (ii) is an Affiliate (as hereinafter defined) of the Corporation
and at any time within the two-year period immediately prior to the date in
question was the beneficial owner of twenty percent (20%) or more of the Voting
Stock; or

                (iii) is an assignee of or has otherwise succeeded to any shares
of Voting Stock which were at any time within the two-year period immediately
prior to the date in question beneficially owned by any Interested Stockholder,
if such assignment or succession shall have occurred in the course of a
transaction or series of transactions not involving a public offering within the
meaning of the Securities Act of 1933;






<PAGE>

provided, that no person which prior to October 24, 1996 came within the
definition set forth in this sub-paragraph (B), nor any present or future
Affiliate of such a person, shall be considered an Interested Stockholder.

            (C) A person shall be a "beneficial owner" of any Voting Stock:

                (i) which such person or any of its Affiliates or Associates (as
hereinafter defined) beneficially owns, directly or indirectly; or

                (ii) which such person or any of its Affiliates or Associates
has, directly or indirectly (a) the right to acquire (whether such right is
exercisable immediately or only after the passage of time), pursuant to any
agreement, arrangement or understanding or upon the exercise of conversion
rights, exchange rights, warrants or options, or otherwise, or (b) the right to
vote pursuant to any agreement, arrangement or understanding; or

                (iii) which are beneficially owned, directly or indirectly, by
any other person with which such person or any of its Affiliates or Associates
has any agreement, arrangement or understanding for the purpose of acquiring,
holding, voting or disposing of any shares of Voting Stock.

            (D) For the purposes of determining whether a person is an
Interested Stockholder pursuant to sub-paragraph (B) of this paragraph 3, the
number of shares of Voting Stock deemed to be outstanding shall include shares
deemed owned through application of subparagraph (C) of this paragraph 3 but
shall not include any other shares of Voting Stock which may be issuable
pursuant to any agreement, arrangement or understanding or upon exercise of
conversion rights, warrants or options, or otherwise.

            (E) The terms "Affiliate" and "Associate" shall have the respective
meanings ascribed to such terms in Rule 12b-2 of the General Rules and
Regulations under the Securities Exchange Act of 1934, as in effect on October
24, 1996.

            (F) The term "Subsidiary" means any corporation of which a majority
of any class of equity security is owned, directly or indirectly, by the
Corporation; provided, however, that for the purposes of the definition of
Interested Stockholder set forth in subparagraph (B) of this paragraph 3, the
term "Subsidiary" shall mean only a corporation of which a majority of each
class of equity security is owned, directly or indirectly, by the Corporation.

            (G) The term "Continuing Director" means any member of the Board of
Directors of the Corporation who is unaffiliated with the Interested Stockholder
and was a member of the Board prior to the time that the Interested Stockholder
became an Interested Stockholder, and any successor of a Continuing Director who
is unaffiliated with the Interested Stockholder and is recommended or elected to
succeed a Continuing Director by a majority of Continuing Directors, provided
that such recommendation or election shall only be effective if made at a
meeting at which a Continuing Director Quorum is present.

            (H) The term "Continuing Director Quorum" means three Continuing
Directors capable of exercising the powers conferred upon them under the
provisions of the Certificate of Incorporation or By-Laws of the Corporation or
by law.







<PAGE>

            (I) The term "Fair Market Value" means: (i) in the case of stock,
the highest closing sale price during the 30-day period immediately preceding
the date in question of a share of such stock on the principal United States
securities exchange registered under the Securities Exchange Act of 1934 on
which such stock is listed, or, if such stock is not listed on any such
exchange, the highest closing bid quotation with respect to a share of such
stock during the 30-day period preceding the date in question on the National
Association of Securities Dealers, Inc. Automated Quotations System or any
system then in use, or if no such quotations are available, the fair market
value on the date in question of a share of such stock as determined by the
Board in good faith; and (ii) in the case of property other than cash or stock,
the fair market value of such property on the date in question as determined in
good faith by a majority of Continuing Directors, provided that such
determination shall only be effective if made at a meeting at which a Continuing
Director Quorum is present.

                (i) In the event of any Business Combination in which the
Corporation survives, the phrase "other consideration to be received" as used in
sub-paragraphs (B)(i) and (ii) of paragraph 2 of this Article VI shall include
the shares of Common Stock and/or the shares of any other class of Voting Stock
retained by the holders of such shares.

         4. The Board of Directors shall have discretion to interpret the
meaning of the provisions of this Article VI, and their applicability with
respect to various factual situations, and the determinations of the Board in
such regard shall be conclusive and binding.

         5. Nothing contained in this Article VI shall be construed to relieve
any Interested Stockholder from any fiduciary obligation imposed by law.

         6. Notwithstanding any other provisions of this Certificate of
Incorporation or the By-laws of the Corporation (and notwithstanding the fact
that a lesser percentage may be specified by law, this certificate of
incorporation or the by-laws of the Corporation), the affirmative vote of the
holders of eighty percent (80%) or more of the outstanding shares of each class
of Voting Stock shall be required to amend or repeal, or adopt any provisions
inconsistent with, this Article VI.



                                   ARTICLE VII

         A director of the Corporation shall not be personally liable to the
Corporation or its 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) 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. Any repeal or modification of
this Article VII shall not adversely affect any right or protection of a
director of the Corporation existing at the time of such repeal or modification.
The liability of a director of the Corporation shall be further eliminated or
limited to the fullest extent allowable under Delaware Law, as it may in the
future be amended.






<PAGE>


                                  ARTICLE VIII

         In furtherance and not in limitation of the power conferred upon the
Board of Directors by law, the Board of Directors shall have power to adopt,
amend and repeal from time to time by-laws of the Corporation.

         IN WITNESS WHEREOF, said PREMIER RESEARCH WORLDWIDE, LTD. has caused
its corporate seal to be hereunto affixed and this certificate to be signed by
Joan Carter, its Chairman of the Board, and attested by James H. Carll, its
Assistant Secretary, this 18th day of November, 1996.

                                          PREMIER RESEARCH WORLDWIDE, LTD.

                                          By: Joan Carter
                                              ----------------------------------
                                              Joan Carter, Chairman of the Board
[Corporate Seal]

Attest:

By: James H. Carll
    -------------------------
    James H. Carll,
    Assistant Secretary






<PAGE>


                            CERTIFICATE OF AMENDMENT
                                       TO
                          CERTIFICATE OF INCORPORATION
                                       OF
                        PREMIER RESEARCH WORLDWIDE, LTD.




TO:      THE SECRETARY OF STATE
         STATE OF DELAWARE

         Pursuant to the provisions of Section 242 of the Delaware General
Corporation Law, this Certificate of Amendment is being filed in order to amend
the Certificate of Incorporation of Premier Research Worldwide, Ltd., a Delaware
corporation, as set forth below:

         I. The name of the corporation is Premier Research Worldwide, Ltd.

         II. Article I of the Certificate of Incorporation is amended to read in
its entirety as follows:

                    The name of the Corporation is PRWW, Ltd.

         III. The amendment was approved and adopted at the Annual Meeting of
Shareholders of the Corporation duly held on April 17, 2000.

         IV. The number of shares outstanding, the class of such shares, the
number of shares entitled to vote on the amendment, and the number of shares
voted for and against such amendment are as follows:

         Number of               Number of
         Shares                  Shares                                  Voted
         Outstanding   Class     Entitled To Vote        Voted For       Against

         6,952,297     Common    6,952,297               5,840,978        4,754

         V. This amendment has been duly adopted in accordance with Section 242
of the Delaware General Corporation Law.

         VI. The amendment shall be effective upon the close of business on
April 20, 2000.

DATED: April 17, 2000             PREMIER RESEARCH WORLDWIDE, LTD.

                                   By:  Joel Morganroth, MD
                                        -------------------------
                                        Joel Morganroth, M.D.,
                                        Chairman and Chief Executive Officer








<PAGE>



                            CERTIFICATE OF AMENDMENT
                                       TO
                          CERTIFICATE OF INCORPORATION
                                       OF
                                   PRWW, LTD.




TO:      THE SECRETARY OF STATE
         STATE OF DELAWARE

         Pursuant to the provisions of Section 242 of the Delaware General
Corporation Law, this Certificate of Amendment is being filed in order to amend
the Certificate of Incorporation of PRWW, LTD., a Delaware corporation, as set
forth below:

         I. The name of the corporation is PRWW, LTD.

         II. The Certificate of Incorporation is hereby amended as follows:

                  (a) Article I of the Certificate of Incorporation is amended
to read in its entirety as follows:

                      The name of the Corporation is eResearchTechnology, Inc.


         III. The amendment was approved and adopted at the Annual Meeting of
Shareholders of the Corporation duly held on April 24, 2001.

         IV. The number of shares outstanding, the class of such shares, the
number of shares entitled to vote on the amendment, and the number of shares
voted for and against such amendment are as follows:


          Number of Shares
          Outstanding and                      Voted      Voted          Vote
          Entitled to Vote        Class         For       Against       Abstain
          -----------------      ------      ---------    -------       -------
          6,970,887              Common      6,176,734    116,227        2,934


         V. This amendment has been duly adopted in accordance with Section 242
of the Delaware General Corporation Law.

         VI. The amendment shall be effective upon the close of business on
April 26th, 2001.

DATED:  April 24, 2001                      PRWW, LTD.

                                            By:   Joel Morganroth, MD
                                               -------------------------------
                                                  Joel Morganroth, M.D.
                                                  Chairman




<PAGE>


                            CERTIFICATE OF AMENDMENT
                                       OF
                          CERTIFICATE OF INCORPORATION
                                       OF
                            eResearchTechnology, Inc.

            eResearchTechnology, Inc., a corporation organized and existing
under and by virtue of the General Corporation Law of the State of Delaware,

DOES HEREBY CERTIFY THAT:

FIRST: The Board of Directors of eResearchTechnology, Inc. (the "Corporation"),
at a meeting held on February 4, 2003 at which a quorum was present and acting
throughout, duly adopted a resolution setting forth a proposed amendment of the
Restated Certificate of Incorporation of the Corporation, declaring the
amendment to be advisable and calling for consideration of the amendment by the
stockholders of the Corporation. The amendment is as follows:

                  The first paragraph of Article IV of the Restated Certificate
         of Incorporation of eResearchTechnology, Inc. is amended to read in its
         entirety as follows:

                  "The aggregate number of shares which the corporation shall
         have the authority to issue is 50,500,000, by classes and par value of
         shares as follows:

                  Class                      No. of Shares   Par Value Per share
                  -----                      -------------   -------------------
                  Common..................   50,000,000      $ 0.01

                  Preferred...............      500,000      $10.00"

SECOND: Thereafter, pursuant to a resolution of the Board of Directors, the
holders of a majority of the outstanding shares of the Corporation's Common
Stock, constituting the only class of capital stock of the Corporation entitled
to vote thereon, voted in favor of the amendment at a meeting held on April 22,
2003.

THIRD: Such amendment was duly adopted in accordance with the provisions of
Section 242 of the General Corporation Law of the State of Delaware.

IN WITNESS WHEREOF, the Corporation has caused this Certificate of Amendment to
be signed by its duly authorized officer this 28th day of April, 2003.

                                             eResearchTechnology, Inc.



                                             By: Joel Morganroth
                                                 ------------------------
                                                 Joel Morganroth, M.D.,
                                                 Chairman of the Board