In the Original Investigation by Graham and Malaty titled "Alendronate and Naproxen Are Synergistic for Development of Gastric Ulcers," published in the January 8, 2001, issue of the ARCHIVES (Arch Intern Med. 2001;161:107-110), the number of days of treatment was reported incorrectly. On page 108, lines 10 and 13 of the first paragraph of the "Subjects and Methods" section, the number of days should have read 10, and line 14 should have read "11th day." In the sixth line of the third paragraph of the same section, the sentence should have read "Videoendoscopy was repeated after 10 days of treatment." In Table 3 on page 109, the title should have read "Endoscopic Scores for Mucosal Damage After 10 Days of Drug Therapy."