April 13, 2005


Mail Stop 0306

David L Roland
Vice President
Input/Output Inc.
12300 Parc Crest Drive
Stafford, Texas 77477

	Re:	Input/Output Inc.
		Registration Statement on Form S-3
		Filed March 28, 2005
		File No. 333-123632

Dear Mr. Roland:

      This is to advise you that we have reviewed only those
portions
of your registration statement that relate to the comments below.
Where indicated, we think you should revise your filing in
response
to these comments.  If you disagree, we will consider your
explanation as to why our comments are inapplicable or a revision
is
unnecessary.  Please be as detailed as necessary in your
explanation.
You may decide it is appropriate to provide us with supplemental
information so we may better understand your disclosure.  After
reviewing this information, we may or may not raise additional
comments.

      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or on any other
aspect
of our review.  Feel free to call us at the telephone numbers
listed
at the end of this letter.

Fee Table

1. We note that you are seeking to register for resale shares of
common stock issuable upon conversion of up to an additional
40,000
shares of Series D preferred stock that may be purchased by
Fletcher
in the future.  Please note that it does not appear to be
appropriate
to register the shares of common stock underlying the additional
40,000 shares of Series D preferred stock that this time since
Fletcher has neither purchased nor is irrevocably bound to
purchase
the additional 40,000 shares.  Please revise accordingly.  Refer
to
Item 3S(b) of the Securities Act section of the March 1999
supplement
to the Division of Corporation Finance Manual of Publicly
Available
Telephone Interpretations.


2. We note that you are registering the resale of shares of common
stock that may be issued as payment of future dividends payable
with
respect to the outstanding shares of Series D-1 preferred stock as
well as shares of common stock that may be issued as payment of
future dividends payable with respect to shares of Series D
preferred
stock that may be purchased by Fletcher in the future.  Please
note
that you may only register the resale of shares of common stock
that
may be issued as payment of future dividends payable with respect
to
the shares of Series D-1 preferred stock that were issued and
outstanding at the time of filing of this registration statement.
In
addition, the number of such shares being registered for resale
must
be based on a good faith estimate of the number of shares that may
be
issued as payment of those future dividends.  Please revise
accordingly.  Please also supplementally explain to us how you
calculated the number of shares that are being registered for
resale
following the issuance of those shares as payment of future
dividends.

3. It is unclear what "anti-dilution adjustments" are intended to
be
covered by the last sentence of Note (1) to the registration fee
table.  Please supplementally provide us with a detailed listing
of
all "anti-dilution adjustments" intended to be covered which
appropriately identifies the location of all such anti-dilution
provisions by document, section, paragraph, subparagraph, etc.  In
addition, please note that you may not register the resale of an
indeterminate number of additional shares that may be issued
pursuant
to floating or adjustable purchase or conversion prices, pursuant
to
"make-whole" or similar provisions compensating investors for the
dilution associated with future sales of common stock at prices
lower
than the current conversion or exercise prices of outstanding
convertible securities, or pursuant to any other anti-dilution
provisions other than stock splits, stock dividends or similar
transactions contemplated by Rule 416 of the Securities Act.
Accordingly, you must make a good faith estimate of the maximum
number of shares of common stock that you may issue pursuant to
such
floating or adjustable purchase or conversion prices or anti-
dilution
provisions to determine the number of shares to register for
resale.
If the actual number of shares issued and to be registered for
resale
turns out to be greater than that estimate, you must file a new
registration statement to register the additional securities.
Please
revise Note (1) to the registration fee table so that it is
consistent with the foregoing, and supplementally explain to us
how
you calculated the number of shares that are being registered for
resale following the issuance of those shares pursuant to such
floating or adjustable purchase or conversion prices or anti-
dilution
provisions.

      As appropriate, please amend your registration statement in
response to these comments.  You may wish to provide us with
marked
copies of the amendment to expedite our review.  Please furnish a
cover letter with your amendment that keys your responses to our
comments and provides any requested supplemental information.
Detailed cover letters greatly facilitate our review.  Please
understand that we may have additional comments after reviewing
your
amendment and responses to our comments.

      We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filings reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts relating to a company`s disclosure, they
are
responsible for the accuracy and adequacy of the disclosures they
have made.

	Notwithstanding our comments, in the event the company
requests
acceleration of the effective date of the pending registration
statement, it should furnish a letter, at the time of such
request,
acknowledging that:

* should the Commission or the staff, acting pursuant to delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;

* the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and

* the company may not assert staff comments and the declaration of
effectiveness as a defense in any proceeding initiated by the
Commission or any person under the federal securities laws of the
United States.

	In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in connection with our review of
your
filing or in response to our comments on your filing.

      We will consider a written request for acceleration of the
effective date of the registration statement as a confirmation of
the
fact that those requesting acceleration are aware of their
respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering
of the securities specified in the above registration statement.
We
will act on the request and, pursuant to delegated authority,
grant
acceleration of the effective date.

      We direct your attention to Rules 460 and 461 regarding
requesting acceleration of a registration statement.  Please allow
adequate time after the filing of any amendment for further review
before submitting a request for acceleration.  Please provide this
request at least two business days in advance of the requested
effective date.

	If you have any questions, please call Alan Morris at (202)
942-
1980 or the undersigned at (202) 942-7924


      Sincerely,



						David Ritenour
      Special Counsel

cc:	Marc A Folladori (Fulbright & Jaworsky)
      Via Facsimile (713) 651-5246
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David L Roland, Vice President
Input/Output Inc.
April 13, 2005
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