EXHIBIT 99.1 GIANT INDUSTRIES, INC. NEWS RELEASE Contact: Mark B. Cox Executive Vice President, Treasurer, & Chief Financial Officer (480) 585-8888 FOR IMMEDIATE RELEASE September 12, 2005 GIANT INDUSTRIES, INC. ANNOUNCES COMMON STOCK OFFERING Scottsdale, AZ - September 12, 2005 - Giant Industries, Inc. (NYSE: GI) today announced that it has agreed to sell 1,000,000 shares of its common stock to Banc of America Securities LLC, subject to customary closing conditions. All shares are being offered by the Company. Banc of America Securities LLC will act as sole underwriter for the offering. The Company, which recently completed two acquisitions using cash on hand, intends to use the net proceeds from this offering for general corporate purposes, including to test and take other actions required to place its newly acquired crude oil pipeline in service and for possible future acquisitions. The shares of common stock will be issued pursuant to an effective shelf registration statement that was previously filed with the Securities and Exchange Commission. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction. Copies of the prospectus supplement relating to these securities may be obtained, when available, from Banc of America Securities LLC, Attn: Prospectus Department, 100 West 33rd Street, New York, New York 10001 or via e-mail at dg.prospectus_distribution@ bofasecurities.com. Company Information and Forward Looking Statements Giant Industries, Inc., headquartered in Scottsdale, Arizona, is a refiner and marketer of petroleum products. Giant owns and operates one Virginia and two New Mexico crude oil refineries, a crude oil gathering pipeline system based in Farmington, New Mexico, which services the New Mexico refineries, finished products distribution terminals in Albuquerque, New Mexico and Flagstaff, Arizona, a fleet of crude oil and finished product truck transports, and a chain of retail service station/convenience stores in New Mexico, Colorado, and Arizona. Giant is also the parent company of Phoenix Fuel Co., Inc. and Dial Oil Co., both of which are wholesale petroleum products distributors. This press release contains forward-looking statements that involve known and unknown risks and uncertainties. Forward- looking statements are identified by words or phrases such as "believes," "expects," "anticipates," "estimates," "should," "could," "plans," "intends," "will," variations of such words and phrases, and other similar expressions. While these forward- looking statements are made in good faith, and reflect the Company's current judgment regarding such matters, actual results could vary materially from the forward-looking statements. Important factors that could cause actual results to differ from forward-looking statements include, but are not limited to our success in completing the offering of common stock and other risks detailed from time to time in the Company's filings with the Securities and Exchange Commission. All subsequent written and oral forward-looking statements attributable to the Company, or persons acting on behalf of the Company, are expressly qualified in their entirety by the foregoing. Forward-looking statements made by the Company represent its judgment on the dates such statements are made. The Company assumes no obligation to update any forward-looking statements to reflect new or changed events or circumstance.