Of 7 patients with Barrett''s esophagus, 2 had acute upper gastrointestinal (GI) tract bleeding, 2 had slow chronic upper GI tract bleeding, and 3 had dysphagia and weight loss. At upper GI trace endoscopy, 1- to 2-cm ulcers were seen in all 7 patients in the distal esophagus. Of the 7 patients, 4 also had stricture of varying severity in the distal esophagus. Serial esophageal mucosal biopsy specimens in all 7 patients revealed specialized columnar epithelium distal to 28 cm from the incisor teeth. Of the 7 patients, 5 were treated with intensive antacid [Al(OH)3 and Mg(OH)2] therapy for 8 wk, but the ulcers had no healed after this period of treatment as assessed endoscopically. These 5 patients and 2 more then started therapy with cimetidine [histamine-2 blocker; CM], 1.2 g/day. Repeat endoscopy 4 wk and 8 wk after institution of CM therapy revealed complete healing of the esophageal ulcers in 6 of the 7 patients. One patient needed 16 wk of CM therapy before his ulcer had healed completely. CM therapy was not effective in preventing restricture of the esophagus. Two patients underwent biopsy 18 mo. after successful treatment; gastric epithelium had not reverted to squamous epithelium.