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                                                                   EXHIBIT 99.1


                            [INPUT/OUTPUT LOGO HERE]


NEWS RELEASE

For further information contact:
C. Robert Bunch
Chief Administrative Officer
(281) 933-3339
================================================================================
TUESDAY, OCTOBER 10, 2000



                            CHANGE IN FISCAL YEAR END

         HOUSTON - Input/Output, Inc. (NYSE: IO) today announced that effective
December 31, 2000 the Company's fiscal year-end will change from May 31 to
December 31. Accordingly, the Company intends to file a transition report on
Form 10-K as of and for the seven months ending December 31, 2000. A Quarterly
Report on Form 10-Q will be filed for the three months ending November 30, 2000
based on the Company's current fiscal period.

         In commenting on the change, Tim Probert, the Company's President and
Chief Executive Officer said, "Adopting a calendar year-end for our fiscal year
will better align the Company's financial reporting periods both with the
industry sector and the Company's business strategy."

         Input/Output is a world leader in seismic acquisition imaging
technology for land, transition zone and marine exploration and production. The
Company specializes in driving to market technology that creates value for the
energy industry in the areas of 2D, 3D, 4D, and multi-component seismic data
acquisition.

     This press release contains forward-looking information, which is subject
to the provisions of the Private Securities Litigation Reform Act of 1995,
including statements relating to, the potential effects of the Company's
financial reporting periods. Investors are cautioned that all forward-looking
statements are subject to certain risks and uncertainties that could cause
actual results to differ materially from those projected, including risks
associated with the timing and development of, and market acceptance of, the
Company's products and services, technological changes affecting the Company's
product line, industry conditions, risks associated with competition and
competitive pricing pressures, defaults in financed purchase obligations and
changes in contract terms, and risks associated with sales to customers outside
the United States. Additional factors which could affect actual results are
described in the section entitled "Cautionary Statement for Purposes of
Forward-Looking Statements" contained in the Company's report on Form 10-K for
the year ended May 31, 2000 and the Company's Quarterly Reports on Form 10-Q
filed thereafter.