The clinical course of gastric and duodenal ulcer and the efficacy of H2 blockers in ulcer healing and the prevention of relapse in cirrhotic liver patients were studied. Seventy-four cirrhotic patients with endoscopically proven acute gastric ulcer (30), duodenal ulcer (34) or a combination of both gastric and duodenal ulcers (10) were treated for six weeks with either Cimetidine 800 mg/daily (27) or Ranitidine 300 mg/daily (47). Of the 77 patients 49 (66.2%) were healed after therapy, 11 cases (14.8%) remained unhealed even after two additional cycles of the same treatment and four were lost to follow-up. After an endoscopically proven healing of the active ulcer, 51 patients took part in the long-term study over a mean period of 24 months: 21.5% of the 27 patients were treated with a maintenance dosage of H2 blockers and 29.1% of the 24 patients left without therapy relapsed during the first year. We conclude that the ulcer healing rate with H2 blockers is lower and the relapse rate higher in cirrhotic patients than in the general ulcer population.