Mail Stop 6010
      December 20, 2005


VIA U.S. MAIL AND FACSIMILE (408) 544-6414

Nathan Sarkisian
Chief Financial Officer
Altera Corporation
101 Innovation Drive
San Jose, CA  95134

      Re:	Altera Corporation
		Form 10-K for the year ended December 31, 2004
      Filed March 11, 2005
		File No. 000-16617

Dear Mr. Sarkisian:


      We have reviewed your response dated December 7, 2005 and
related filings and have the following comments.  We have limited
our
review of your filing to those issues we have addressed in our
comments.  Where indicated, we think you should revise your
document
in response to these comments.  If you disagree, we will consider
your explanation as to why our comment is inapplicable or a
revision
is unnecessary.  Please be as detailed as necessary in your
explanation.  In some of our comments, we may ask you to provide
us
with information so we may better understand your disclosure.
After
reviewing this information, we may 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 any other aspect
of
our review.  Feel free to call us at the telephone numbers listed
at
the end of this letter.




Form 10-K for the year ended December 31, 2004

Consolidated Financial Statements

Note 2.  Significant Accounting Policies, page 35

Revenue Recognition, page 37

1. We note your response to prior comment two in our letter dated
November 22, 2005. We see that you defer revenue on products sold
to
distributors due to the right of return.  Please tell us why you
defer revenue related to your sales returns and allowances and the
accounting literature you relied on for this treatment. If you do
not
meet the criteria under SFAS 48 to recognize revenue because of
your
inability to estimate returns, clarify the basis for recognizing
the
sale on your balance sheet. In addition, clarify the nature of the
reserves for OEM sales returns and allowances and why this is
included in the deferred income liability. Your response should
indicate how this accounting treatment complies with SAB 101, SAB
13A.4. and SFAS 48.
2. As a related matter, please provide us with the composition of
your deferred income and allowances on sales to distributors at
the
most recent balance sheet date, and indicate the amount of
deferred
income related to rights of return. Please also tell us your
history
of reversals of deferred income and allowances of sales to
distributors.  In addition, tell us when you expect to recognize
this
deferral in the statements of income.

      As appropriate, please respond to these comments within 10
business days or tell us when you will provide us with a response.
Please furnish a cover letter with your response that keys your
responses to our comments and provides any requested information.
Detailed cover letters greatly facilitate our review.  Please
understand that we may have additional comments after reviewing
your
responses to our comments.

	You may contact Kristin Lochhead at (202) 551-3664 or me at
(202) 551-3676 if you have questions.  In this regard, please do
not
hesitate to contact Martin James, Senior Assistant Chief
Accountant
at (202) 551-3671 with any other questions.


      Sincerely,



      Brian Cascio
      Accounting Branch Chief
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Mr. Sarkisian
Altera Corporation
December 20, 2005
Page 2