Komag Calls for Partial Mandatory Redemption of Senior Secured Notes Due 2007.

Komag, Incorporated is calling today for the partial redemption on October 21, 2003, $12,100,000 principal amount of its Senior Secured Notes Due 2007 (the "Notes"). The aggregate principal amount outstanding of the Notes is approximately $130.8 million. The CUSIP numbers for the Notes being called for redemption is 500453 AA 3 and 500453 AC 9. The Notes to be redeemed will be selected in accordance with the applicable procedures of The Depository Trust Company and the indenture under which the Notes were issued.

(Logo: http://www.newscom.com/cgi-bin/prnh/19990816/KOMGLOGO )

Upon redemption, holders whose Notes have been selected for redemption having CUSIP No. 500453 AA 3 will receive $10.1861 per Note (consisting of $10.1725 in principal amount at maturity plus $0.0136 of accrued and unpaid interest thereon from October 15, 2003 to October 20, 2003) and holders whose Notes have been selected for redemption and having CUSIP No. 500453 AC 9 will receive $14.1988 (consisting of $14.1799 in principal amount at maturity plus $0.0189 of accrued and unpaid interest thereon from October 15, 2003 to October 20, 2003). Any of the Notes called for redemption will be automatically redeemed in part on October 21, 2003, and no further interest will accrue.

A Notice of Redemption is being mailed to all registered holders of the Notes. Copies of the Notice of Redemption may be obtained from The Bank of New York, the Paying Agent, by calling Michael Pitfick at 212-815-3036. The address of The Bank of New York is 101 Barclay Street, 21W, New York, NY 10286.

About Komag

Founded in 1983, Komag is the world's largest independent supplier of thin-film disks, the primary high-capacity storage medium for digital data. Komag leverages the combination of its world-class U.S. research and development center and Malaysian manufacturing operations to produce disks that meet the high-volume, stringent quality, low cost and demanding technology needs of its customers. By enabling rapidly improving storage density at ever-lower cost per gigabyte, Komag seeks to create extraordinary value for consumers of computers, enterprise storage systems and electronic appliances such as digital video recorders, game boxes and consumer electronic storage systems.

For more information about Komag, visit Komag's Internet home page at http://www.komag.com/ . The Investors section of the website provides a variety of financial and investor information, including an investor presentation. To request an investor packet, call Komag's Investor Relations at 408-576-2901.

CONTACT: investors and press, Kathy Bayless, Chief Financial Officer of Komag, Incorporated, +1-408-576-2000, or ir_web@komag.com

Web site: http://www.komag.com/