SECTION 906 CERTIFICATION


Pursuant to 18 U.S.C. Section 1350, each of the undersigned officers of Calamos
Strategic Total Return Fund (the "Company"), hereby certifies, to his knowledge,
that the Company's Report on Form N-CSR for the period ended April 30, 2004 (the
"Report") fully complies with the requirements of Section 13(a) or 15(d), as
applicable, of the Securities Exchange Act of 1934 and that the information
contained in the Report fairly presents, in all material respects, the financial
condition and results of operations of the Company.

Date: July 6, 2004

/s/ John P. Calamos, Sr.
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Name:  John P. Calamos, Sr.
Title: Principal Executive Officer



/s/ Patrick H. Dudasik
- ------------------------------------------
Name:  Patrick H. Dudasik
Title: Principal Financial Officer


This certificate is furnished pursuant to the requirements of Form N-CSR and
shall not be deemed "filed" for purposes of section 18 of the Securities
Exchange Act of 1934, or otherwise subject to the liability of that section, and
shall not be deemed to be incorporated by reference into any filing under the
Securities Act of 1933 or the Exchange Act of 1934.

A signed original of this certificate required by Section 906 has been provided
to Calamos Strategic Total Return Fund and will be retained by Calamos Strategic
Total Return Fund and furnished to the Securities and Exchange Commission or
staff upon request.




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