<PAGE>

   As filed with the Securities and Exchange Commission on September 17, 1997

                              Registration No. 333-

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

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT

                                      UNDER
                           THE SECURITIES ACT OF 1933

                             Bio-Logic Systems Corp.
               ----------------------------------------------------
             (Exact name of registrant as specified in its charter)

                                    Delaware
               ----------------------------------------------------
         (State or other jurisdiction of incorporation or organization)

                                   36-3025678
               ----------------------------------------------------
                      (I.R.S. employer identification no.)

                  One Bio-Logic Plaza, Mundelein, IL 60060-3700
               ----------------------------------------------------
                    (Address of principal executive offices)

                             1994 Stock Option Plan
                         -------------------------------
                              (Full title of plan)

                            Gabriel Raviv, President
                            Bio-Logic Systems, Corp.
                               One Bio-Logic Plaza
                            Mundelein, IL 60060-3700
                 ----------------------------------------------
                     (Name and address of agent for service)

                                 (847) 949-5200
          -------------------------------------------------------------
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                               Jill M. Cohen, Esq.
                      Bachner, Tally, Polevoy & Misher LLP
                               380 Madison Avenue
                               New York, NY 10017

<PAGE>

===============================================================================
                        CALCULATION OF REGISTRATION FEE
===============================================================================
                                Proposed    Proposed   
                                Maximum     Maximum    
                                Offering    Aggregate              Amount of 
     Title of Securities          to be     Price Per  Offering   Registration
       to be Registered        Registered   Share(2)    Price         Fee    
===============================================================================
Common Stock $.01 par value    400,000(1)     $5.47    $2,188,000  $663.00(3)
===============================================================================

(1)   Pursuant to Rule 416, promulgated under the Securities Act of 1933, as
      amended, an additional undeterminable number of shares of Common Stock is
      being registered to cover any adjustment in the number of shares of Common
      Stock pursuant to the anti-dilution provisions of the 1994 Stock Option
      Plan, as amended.

(2)   Estimated in accordance with Rule 457(h) solely for the purpose of
      calculating the registration fee. The price shown is the average of the
      high and low prices of the Common Stock on September 12, 1997 as reported
      on Nasdaq.

(3)   A payment of  $538.00 is being made herewith, as $125.00 has previously 
      been paid.

                                      -2-
<PAGE>

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.     INCORPORATION OF DOCUMENTS BY REFERENCE

                  The Registration Statement on Form S-8 (File No. 33-62237),
filed by BIO-LOGIC SYSTEMS CORP. (the "Registrant") on August 30, 1995, and the
documents listed below are hereby incorporated by reference into this
Registration Statement, and all documents subsequently filed by the Registrant
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
of 1934, as amended, prior to the filing of a post-effective amendment which
indicates that all securities offered have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be part hereof from the date of
filing such documents:

            (a)   The Registrant's Annual Report on Form 10K-SB 
            (File No. 0-12231) for its fiscal year ending February 28, 1997.

            (b)   The Registrant's quarterly report on Form 10Q-SB for the 
            quarterly period ended May 31, 1997; and

            (c) The Registrant's Registration Statement on Form 8-A, as filed
            with the Securities and Exchange Commission on June 6, 1994 to 
            register the Common Stock, $.01 par value, under Section 12(g) of 
            the Securities and Exchange Act of 1934, as amended.

Item 8.     EXHIBITS

            5     Opinion of Bachner, Tally, Polevoy & Misher LLP, with respect 
                  to the legality of the
                  Common Stock to be registered hereunder

            10.15 1994 Stock Option Plan, as amended

            24(a) Independent Audit's Consent

            24(b) Consent of Bachner, Tally, Polevoy & Misher LLP
                  (contained in Exhibit 5)

                                      -3-
<PAGE>

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 of 1933;

                        (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
                  changed 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) if, in the aggregate, the changes in volume and 
                  price represent no more than 20 percent 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 Securities Exchange Act
                  of 1934 that are incorporated by reference in the registration
                  statement.

                  (2) That, for the purpose of determining any liability under
            the Securities Act of 1933, 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 the registration by means of 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 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

                                      -4-
<PAGE>

      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.

            (h) 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 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 Act and
      will be governed by the final adjudication of such issue.

                                      -5-
<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-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in city of Chicago, State of Illinois, on the 15th day of September,
1997.

                                    BIO-LOGIC SYSTEMS CORP.


                                    By: /S/ GABRIEL RAVIV
                                       -------------------------- 
                                        President and Chief Executive Officer

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

<TABLE>
<CAPTION>

             SIGNATURE                    TITLE                     DATE

<S>                                <C>                           <C>

  /S/ GABRIEL RAVIV              President, Chief Executive     September 15, 1997
-------------------------------  Officer and Director                             
Gabriel Raviv                    (Principle Executive Officer)                    


 /S/ WILLIAM K. ROENITZ          Controller                     September 15, 1997
-------------------------------  (Principal Accounting Officer)                  
William K. Roenitz               

                                 
 /S/ GIL RAVIV                   Director                       September 15, 1997
-------------------------------
Gil Raviv


 /S/ CHARLES Z. WEINGARTEN, M.D. Director                       September 15, 1997
--------------------------------
Charles Z. Weingarten, M.D.


 /S/ IRVING KUPFERBERG           Director                       September 15, 1997
--------------------------------
Irving Kupferberg


 /S/ ALBERT MILSTEIN             Director                       September 15, 1997
--------------------------------
Albert Milstein


 /S/ CRAIG W. MOORE              Director                       September 15, 1997
--------------------------------
Craig W. Moore

</TABLE>

<PAGE>

                               INDEX TO EXHIBITS
                            BIO-LOGIC SYSTEMS CORP.

Exhibit
  NO.                             DESCRIPTION

   5              Opinion of Bachner, Tally, Polevoy & Misher LLP,
                  with respect to the legality of the Common Stock
                  to be registered hereunder

 10.15            1994 Stock Option Plan, as amended

 24(a)            Independent Auditor's Consent

 24(b)            Consent of Bachner, Tally, Polevoy & Misher LLP
                        (contained in Exhibit 5)
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 13655}]
{"company-data": {"conformed-name": "BIO LOGIC SYSTEMS CORP", "cik": "0000355007", "assigned-sic": "3845", "irs-number": "363025678", "state-of-incorporation": "DE", "fiscal-year-end": "0228"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-35773", "film-number": "97681427"}, "business-address": {"street1": "ONE BIO LOGIC PLZ", "city": "MUNDELEIN", "state": "IL", "zip": "60060", "phone": "7089495200"}, "mail-address": {"street1": "ONE BIO LOGIC PLAZA", "city": "MUNDELEIN", "state": "IL", "zip": "60060"}}
As filed with the Securities and Exchange Commission on September 17, 1997

                              Registration No. 333-

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

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT

                                      UNDER
                           THE SECURITIES ACT OF 1933

                             Bio-Logic Systems Corp.
               ----------------------------------------------------
             (Exact name of registrant as specified in its charter)

                                    Delaware
               ----------------------------------------------------
         (State or other jurisdiction of incorporation or organization)

                                   36-3025678
               ----------------------------------------------------
                      (I.R.S. employer identification no.)

                  One Bio-Logic Plaza, Mundelein, IL 60060-3700
               ----------------------------------------------------
                    (Address of principal executive offices)

                             1994 Stock Option Plan
                         -------------------------------
                              (Full title of plan)

                            Gabriel Raviv, President
                            Bio-Logic Systems, Corp.
                               One Bio-Logic Plaza
                            Mundelein, IL 60060-3700
                 ----------------------------------------------
                     (Name and address of agent for service)

                                 (847) 949-5200
          -------------------------------------------------------------
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                               Jill M. Cohen, Esq.
                      Bachner, Tally, Polevoy & Misher LLP
                               380 Madison Avenue
                               New York, NY 10017
===============================================================================
                        CALCULATION OF REGISTRATION FEE
===============================================================================
                                Proposed    Proposed   
                                Maximum     Maximum    
                                Offering    Aggregate              Amount of 
     Title of Securities          to be     Price Per  Offering   Registration
       to be Registered        Registered   Share(2)    Price         Fee    
===============================================================================
Common Stock $.01 par value    400,000(1)     $5.47    $2,188,000  $663.00(3)
===============================================================================

(1)   Pursuant to Rule 416, promulgated under the Securities Act of 1933, as
      amended, an additional undeterminable number of shares of Common Stock is
      being registered to cover any adjustment in the number of shares of Common
      Stock pursuant to the anti-dilution provisions of the 1994 Stock Option
      Plan, as amended.

(2)   Estimated in accordance with Rule 457(h) solely for the purpose of
      calculating the registration fee. The price shown is the average of the
      high and low prices of the Common Stock on September 12, 1997 as reported
      on Nasdaq.

(3)   A payment of  $538.00 is being made herewith, as $125.00 has previously 
      been paid.

                                      -2-
PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.     INCORPORATION OF DOCUMENTS BY REFERENCE

                  The Registration Statement on Form S-8 (File No. 33-62237),
filed by BIO-LOGIC SYSTEMS CORP. (the "Registrant") on August 30, 1995, and the
documents listed below are hereby incorporated by reference into this
Registration Statement, and all documents subsequently filed by the Registrant
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
of 1934, as amended, prior to the filing of a post-effective amendment which
indicates that all securities offered have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be part hereof from the date of
filing such documents:

            (a)   The Registrant's Annual Report on Form 10K-SB 
            (File No. 0-12231) for its fiscal year ending February 28, 1997.

            (b)   The Registrant's quarterly report on Form 10Q-SB for the 
            quarterly period ended May 31, 1997; and

            (c) The Registrant's Registration Statement on Form 8-A, as filed
            with the Securities and Exchange Commission on June 6, 1994 to 
            register the Common Stock, $.01 par value, under Section 12(g) of 
            the Securities and Exchange Act of 1934, as amended.

Item 8.     EXHIBITS

            5     Opinion of Bachner, Tally, Polevoy & Misher LLP, with respect 
                  to the legality of the
                  Common Stock to be registered hereunder

            10.15 1994 Stock Option Plan, as amended

            24(a) Independent Audit's Consent

            24(b) Consent of Bachner, Tally, Polevoy & Misher LLP
                  (contained in Exhibit 5)

                                      -3-
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 of 1933;

                        (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
                  changed 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) if, in the aggregate, the changes in volume and 
                  price represent no more than 20 percent 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 Securities Exchange Act
                  of 1934 that are incorporated by reference in the registration
                  statement.

                  (2) That, for the purpose of determining any liability under
            the Securities Act of 1933, 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 the registration by means of 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 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

                                      -4-
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.

            (h) 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 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 Act and
      will be governed by the final adjudication of such issue.

                                      -5-
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 city of Chicago, State of Illinois, on the 15th day of September,
1997.

                                    BIO-LOGIC SYSTEMS CORP.

                                    By: /S/ GABRIEL RAVIV
                                       -------------------------- 
                                        President and Chief Executive Officer

      Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below by the following persons in the
capacities and as of the date indicated.
SIGNATURE                    TITLE                     DATE
/S/ GABRIEL RAVIV              President, Chief Executive     September 15, 1997
-------------------------------  Officer and Director                             
Gabriel Raviv                    (Principle Executive Officer)                    

 /S/ WILLIAM K. ROENITZ          Controller                     September 15, 1997
-------------------------------  (Principal Accounting Officer)                  
William K. Roenitz               

                                 
 /S/ GIL RAVIV                   Director                       September 15, 1997
-------------------------------
Gil Raviv

 /S/ CHARLES Z. WEINGARTEN, M.D. Director                       September 15, 1997
--------------------------------
Charles Z. Weingarten, M.D.

 /S/ IRVING KUPFERBERG           Director                       September 15, 1997
--------------------------------
Irving Kupferberg

 /S/ ALBERT MILSTEIN             Director                       September 15, 1997
--------------------------------
Albert Milstein

 /S/ CRAIG W. MOORE              Director                       September 15, 1997
--------------------------------
Craig W. Moore
INDEX TO EXHIBITS
                            BIO-LOGIC SYSTEMS CORP.

Exhibit
  NO.                             DESCRIPTION

   5              Opinion of Bachner, Tally, Polevoy & Misher LLP,
                  with respect to the legality of the Common Stock
                  to be registered hereunder

 10.15            1994 Stock Option Plan, as amended

 24(a)            Independent Auditor's Consent

 24(b)            Consent of Bachner, Tally, Polevoy & Misher LLP
                        (contained in Exhibit 5)