We conducted a double-blind, placebo-controlled, multicenter trial comparing the efficacy of famotidine 40 mg administered at bedtime (HS), 20 mg given twice daily (BID), and placebo to relieve heartburn and to heal endoscopically documented esophageal erosions or ulcerations. A total of 338 patients were randomized: 135 to receive famotidine 40 mg HS, 137 to receive famotidine 20 mg BID, and 66 to receive placebo. In the group given famotidine 20 mg BID, there was a significantly greater proportion of patients with complete relief of daytime heartburn, and both famotidine groups demonstrated statistically significant advantages over placebo in global scores or by successful outcome. Antacid consumption was significantly reduced in the group given famotidine 20 mg BID as compared with placebo. Both famotidine regimens resulted in a significantly greater proportion of patients with complete endoscopic healing than placebo, with the BID dosing being numerically superior to the 40-mg HS dose.