As filed with the Securities and Exchange Commission on September 21, 2005
                                   Registration Nos. 333-85268  
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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                             ----------------------
                                             
                        POST-EFFECTIVE AMENDMENT NO. 1 TO
                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933
                           --------------------------
                                               

                             ESCO TECHNOLOGIES INC.
             (Exact Name of Registrant as Specified in Its Charter)

       Missouri                                             43-1554045
(State or Other Jurisdiction of Incorporation            (I.R.S. Employer )
 or Organization)                                         Identification No.

                               9900A Clayton Road
                            St. Louis, MO 63124-1186
          (Address of Principal Executive Offices, Including Zip Code)
          ------------------------------------------------------------
                                           
                ESCO TECHNOLOGIES INC. 2001 STOCK INCENTIVE PLAN
             ESCO TECHNOLOGIES INC. 2004 INCENTIVE COMPENSATION PLAN
                            (Full title of the Plan)

                             Alyson S. Barclay, Esq.
                  Vice President, Secretary and General Counsel
                             ESCO Technologies Inc.
                               9900A Clayton Road
                            St. Louis, MO 63124-1186
                                 (314) 213-7200
 (Name, Address and Telephone Number, Including Area Code, of Agent For Service)
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                                EXPLANATORY NOTE

This  Post-Effective  Amendment to the ESCO  Technologies  Inc. (the  "Company")
Registration  Statements  on Form  S-8  (Nos.  333-117953  and  333-85268)  (the
"Registration Statements"),  which relate to the Company's equity-based employee
benefit  plans,  is filed by the  Company  pursuant  to  Rule 416(b)  under  the
Securities  Act of 1933,  as amended (the  "Securities  Act"),  to reflect a one
hundred  percent  increase  in the number of shares of common  stock,  $0.01 par
value,  of the  Company  (the  "Common  Stock")  covered  by  such  Registration
Statements as a result of the Company's  two-for-one stock split effected in the
form of a one hundred  percent stock  dividend  payable  September 23,  2005, to
shareholders of record on September 9, 2005.

Pursuant to Rule 416(a) under the Securities  Act, the  Registration  Statements
are also  amended to cover any  additional  shares of Common  Stock which may be
issued under the applicable equity-based  compensation plans to prevent dilution
resulting  from  any  subsequent  stock  splits,   stock  dividends  or  similar
transactions.

The contents of the Registration Statements are hereby incorporated by reference
pursuant to General Instruction E on Form S-8.

PART I   INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS
 
Item 1.  Plan Information.
 
          Not required to be filed with this Registration Statement.
 
Item 2. Registrant Information and Employee Plan Annual Information.
 
          Not required to be filed with this Registration Statement.
 
PART II  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
 
Item 3. Incorporation of Documents by Reference.
 
          Not required to be filed with this Registration  Statement pursuant to
          General Instruction E on Form S-8.
 
Item 4. Description of Securities.
 
          Not required to be filed with this Registration  Statement pursuant to
          General Instruction E on Form S-8.
 
Item 5. Interests of Named Experts and Counsel.
 
          Not required to be filed with this Registration  Statement pursuant to
          General Instruction E on Form S-8.

 
Item 6. Indemnification of Directors and Officers.
 
          Not required to be filed with this Registration  Statement pursuant to
          General Instruction E on Form S-8.

Item 7. Exemption from Registration Claimed.

          Not applicable.

Item 8. Exhibits.

Exhibit No.      Description        Filed Herewith or Incorporated by Reference

4.1 Specimen Common Stock Certificate Incorporated  by reference  to  Form 10-Q
                                      for the fiscal  quarter  ended  June 30,
                                      2000, at Exhibit 4(a)

4.2 Specimen Rights Certificate        Incorporated  by reference  to Current  
                                       Report on Form 8-K dated February 3, 
                                       2000,  at Exhibit B to Exhibit 4.1

4.3 Rights Agreement dated as of       Incorporated  by reference  to Current
    September 24, 1990 (as amended     Report on  Form  8-K  dated February 3,
    and  restated  as  of February 3,  2000, at Exhibit 4.1
    2000)  between the  Registrant 
    and  Registrar and Transfer 
    Company, as successor Rights Agent

4.4 Credit  Agreement  dated  as  of   Incorporated  by reference to Form 10-K
    October 6, 2004, among the         for the fiscal year ended September 30,
    Registrant,  Wells Fargo Bank,     2004, at Exhibit 4.4                   
    N.A., as  agent, and the 
    lenders listed therein 

5   Opinion of Counsel

23.1 Consent of Counsel (included 
     in Exhibit 5)

23.2 Consent of KPMG LLP

24   Power of Attorney (included 
     on the Signatures pages
     of the Registration Statements)


Item 9.Undertakings

          Not required to be filed with this Registration  Statement pursuant to
          General Instruction E on Form S-8.

                                   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  Ladue,  state  of  Missouri,  on this  20th day of
September, 2005.

                                              ESCO TECHNOLOGIES INC.

                                              By: /s/ T.B. Martin
                                                  ----------------
                                                  T.B. Martin
                                                  Assistant Secretary and
                                                  Associate General Counsel

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.

Signature                                      Title                 Date

/s/ *                Chairman, Chief Executive Officer and    September 20, 2005
----------------     Director (principal executive officer)   
V. L. Richey, Jr.

/s/ *                President, Chief Operating Officer and  September 20, 2005
----------------     Director                  
C. J. Kretschmer

/s/ *                Vice President and Chief Financial      September 20, 2005
--------------       Officer (principal financial and      
G. E. Muenster       accounting officer)

/s/ *                 Director                               September 20, 2005
---------------                                     
W. S. Antle III

/s/ *                 Director                               September 20, 2005
---------------                                                           
J. M. McConnell

/s/ *                 Director                               September 20, 2005
------------                                                           
L. W. Solley

/s/ *                  Director                              September 20, 2005
-------------                                                          
J. M. Stolze

/s/ *                  Director                               September 20, 200
--------------                                                           
D. C. Trauscht

/s/ *                  Director                              September 20, 2005
------------                                                          
J. D. Woods

*/s/T.B. Martin                                              September 20, 2005
---------------
T.B. Martin                                                           
Assistant Secretary and
Associate General Counsel
By power of attorney



                                  EXHIBIT INDEX

Exhibits are listed by number  corresponding to the Exhibit Table of Item 601 in
Regulation S-K.

5             Opinion of Counsel.
23.1          Consent of Counsel (included in Exhibit 5)
23.2          Consent of KPMG LLP.
24            Power of Attorney (included on the Signatures pages of the 
              Registration Statements)

See Item 8 for a list of exhibits incorporated by reference.