<PAGE>   1
    As Filed With the Securities and Exchange Commission on March 14, 1997
--------------------------------------------------------------------------------
                                                        Registration No. 333-


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington. D.C. 20549


                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

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

                            MICRO THERAPEUTICS, INC.
             (Exact name of registrant as specified in its charter)


                 Delaware                               33-0569235
      (State or other jurisdiction of       (I.R.S. Employer Identification No.)
       incorporation or organization)

                             1062 Calle Negocio #F,
                         San Clemente, California 92673
               (Address of Principal Executive Offices) (Zip Code)

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

                          EMPLOYEE STOCK PURCHASE PLAN

                            (Full title of the plan)


              George Wallace, President and Chief Executive Officer
                            Micro Therapeutics, Inc.
              1062 Calle Negocio #F, San Clemente, California 92673
                     (Name and address of agent for service)

                                 (714) 361-0616
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                              Bruce Feuchter, Esq.
          Stradling, Yocca, Carlson & Rauth, a Professional Corporation
      660 Newport Center Drive, Suite 1600, Newport Beach, California 92660

                       [cover page continued on next page]


<PAGE>   2
                             [cover page continued]


                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                                   Proposed Maximum         Proposed Maximum
  Title of Securities        Amount To Be              Offering            Aggregate Offering     Amount of Registration Fee
   To Be Registered         Registered (1)        Price Per Share (2)           Price (2)
------------------------ ---------------------- ------------------------ ------------------------ ----------------------------
<S>                         <C>                         <C>                     <C>                         <C>    
  Common Stock, $.001
       par value            100,000 shares              $6.1625                 $616,250                    $186.75
------------------------ ---------------------- ------------------------ ------------------------ ----------------------------
</TABLE>

(1)   Includes additional shares of Common Stock that may become issuable
      pursuant to the anti-dilution adjustment provisions of the Company's
      Employee Stock Purchase Plan (the "Purchase Plan").

(2)   In accordance with Rule 457(h), the aggregate offering price of the
      100,000 shares of Common Stock registered hereby, which are issuable under
      the Purchase Plan, was estimated using a per share price of $6.1625, or
      85% of $7.25 (as determined in accordance with Rule 457(c), using the
      average of the high and low price reported by the Nasdaq National Market
      for the Common Stock on March 11, 1997), which price per share is the
      estimated basis at which the shares will be issued pursuant to the
      Purchase Plan.


<PAGE>   3

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

      The following documents are incorporated herein by reference:

      (a) The Registrant's Prospectus dated February 18, 1997 filed pursuant to
Rule 424(b) of the Securities Act of 1933, as amended (the "Act").

      (b) All other reports filed by the Registrant pursuant to Section 13(a) or
15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
since the end of the fiscal year covered by the Prospectus referred to in (a)
above.

      (c) The description of the Registrant's Common Stock that is contained in
the Registrant's Registration Statement on Form 8-A filed under Section 12 of
the Exchange Act, including any amendment or report filed for the purpose of
updating that description.

      All documents subsequently filed by the Registrant pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all of such securities then remaining unsold, shall be
deemed to be incorporated herein by reference and to be a part hereof from the
date of filing of such documents, except as to any portion of any future annual
or quarterly report to stockholders or document that is not deemed filed under
such provisions. For the purposes of this registration statement, any statement
in a document incorporated by reference shall be deemed to be modified or
superseded to the extent that a statement contained in this registration
statement modifies or supersedes a statement in such document. Any statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this registration statement.

Item 4.  Description of Securities.

      Not applicable.

Item 5.  Interests of Named Experts and Counsel.

      Not applicable.

Item 6.  Indemnification of Directors and Officers.

      (a) As permitted by the Delaware General Corporation Law, the Registrant's
Bylaws provide for indemnification of its directors and officers to the fullest
extent permitted by the Delaware General Corporation Law. In addition, the
Registrant's Certificate of Incorporation eliminates the liability of directors
to the Registrant or its stockholders for monetary damages for breach of
fiduciary duty as a director, except to the extent otherwise required by the
Delaware General Corporation Law.

      (b) The Registrant has entered into indemnification agreements with each
of its directors and executive officers. The indemnification agreements provide
for the indemnification of directors and officers of the Company against any and
all expenses, judgments, fines, penalties and amounts paid in settlement, to the
fullest extent permitted by law. The Registrant also maintains directors and
officers liability insurance, under which directors and officers are insured
against certain expenses in connection with the defense of actions, suits or
proceedings, and certain liabilities which might be imposed as a result of such
actions, suits or proceedings, to which they are parties by reason of being or
having been such directors or officers.


                                       2

<PAGE>   4

Item 7.  Exemption from Registration Claimed.

         Not applicable.

Item 8.  Exhibits.

         The following exhibits are filed as part of this Registration
Statement:

<TABLE>
<CAPTION>
            Number                         Description
            ------                         -----------
            <S>         <C>
            4.3         Employee Stock Purchase Plan, incorporated by reference
                        to Exhibit 10.8 to the Company's Registration Statement
                        on Form SB-2, No. 333-17345, effective on February 14,
                        1997.

            5.1         Opinion of Stradling, Yocca, Carlson & Rauth, a
                        Professional Corporation, Counsel to the Registrant.

            23.1        Consent of Stradling, Yocca, Carlson & Rauth, a
                        Professional Corporation (included in the Opinion filed
                        as Exhibit 5.1).

            23.2        Consent of Coopers & Lybrand L.L.P., independent
                        accountants.

            24.1        Power of Attorney (included on signature page to the
                        Registration Statement at page S-1).
</TABLE>

Item 9.  Undertakings.

      (a)   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 this 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;

                  (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) shall
not apply if the information required to be included in a post-effective
amendment by these paragraphs is contained in periodic reports filed by the
registrant pursuant to Section 13 or Section 15(d) of the Exchange 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

<PAGE>   5

            (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) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act 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.

      (h) Insofar as indemnification for liabilities arising under the
Securities Act 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 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.



                                       4

<PAGE>   6

                                   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-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of San Clemente, State of California, on the 13th day of
March, 1997.

                                   MICRO THERAPEUTICS, INC.                    
                                                                               
                                   By:   /s/ George Wallace                    
                                         --------------------------------------
                                         George Wallace                        
                                         President and Chief Executive Officer 
                                         (Principal Executive Officer)         


                                POWER OF ATTORNEY

      We, the undersigned officers and directors of Micro Therapeutics, Inc., do
hereby constitute and appoint George Wallace and Thomas Berryman, or either of
them, as our true and lawful attorneys and agents, to do any and all acts and
things in our name and behalf in our capacities as directors and officers and to
execute any and all instruments for us and in our names in the capacities
indicated below, which said attorneys and agents, or either of them, may deem
necessary or advisable to enable said corporation to comply with the Securities
Act of 1933, as amended, and any rules, regulations and requirements of the
Securities and Exchange Commission in connection with this Registration
Statement, including specifically, but without limitation, power and authority
to sign for us or any of us in our names and in the capacities indicated below,
any and all amendments (including post-effective amendments) hereto or any
related registration statement that is to be effective upon filing pursuant to
Rule 462(b) under the Securities Act of 1933, as amended; and we do hereby
ratify and confirm all that the said attorneys and agents, or either of them,
shall 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 date indicated.

<TABLE>
<CAPTION>
       Signature                       Title                       Date
       ---------                       -----                       ----
<S>                             <C>                            <C> 
    /s/ George Wallace          President,  Chief Executive    March 13, 1997
---------------------------     Officer and Director
      George Wallace            



    /s/ Thomas Berryman         Vice  President  of Finance    March 13, 1997
---------------------------     and Chief Financial 
      Thomas Berryman           Officer (Principal 
                                Financial and Accounting 
                                Officer)                    
                                


 /s/ H. Dubose Montgomery       Chairman of the Board and      March 13, 1997
---------------------------     Director
   H. Dubose Montgomery        
</TABLE>




                                      S-1


<PAGE>   7

<TABLE>
<S>                             <C>                            <C> 
     /s/ Wende Hutton           Director                       March 13, 1997
---------------------------     
       Wende Hutton



      /s/ Dick Allen            Director                       March 13, 1997
---------------------------     
        Dick Allen
</TABLE>




                                      S-2

<PAGE>   8

                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
Exhibit
Number         Description
------         -----------
<S>            <C>
4.3            Employee Stock Purchase Plan, incorporated by reference to
               Exhibit 10.8 to the Company's Registration Statement on Form
               SB-2, No. 333-17345, effective on February 14, 1997.

5.1            Opinion of Stradling, Yocca, Carlson & Rauth, a Professional
               Corporation, Counsel to the Registrant.

23.1           Consent of Stradling, Yocca, Carlson & Rauth, a Professional
               Corporation (included in the Opinion filed as Exhibit 5.1).

23.2           Consent of Coopers & Lybrand L.L.P., independent accountants.

24.1           Power of Attorney (included on signature page to the Registration
               Statement at page S-1).
</TABLE>



                                      S-3