Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section
906 of the Sarbanes-Oxley Act of 2002

In connection with the attached Report of John Hancock Investment Trust III (the
"registrant") on Form N-CSR to be filed with the Securities and Exchange
Commission (the "Report"), each of the undersigned officers of the registrant
does hereby certify that, to the best of such officer's knowledge:

1. The Report fully complies with the  requirements of Section 13(a) or 15(d) of
the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material
respects, the financial condition and results of operations of the registrant as
of, and for, the periods presented in the Report.


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Maureen Ford Goldfarb
Chairman, President and Chief Executive Officer

Dated: December 18, 2003



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Richard A. Brown
Senior Vice President and Chief Financial Officer

Dated: December 18, 2003

A signed original of this written statement, required by Section 906, has been
provided to the registrant and will be retained by the registrant and furnished
to the Securities and Exchange Commission or its staff upon request.