The effect of pirenzepine and cimetidine on healing, symptoms and relapse rate of duodenal ulcer was studied in a placebo-controlled double-blind trial. Cimetidine (1 g daily) was superior at the beginning of therapy to a low dose of pirenzepine (75 mg daily) and placebo with regard to symptoms. No significant differences in ulcer healing were found between the 3 groups of treatment. The relapse rate after treatment with pirenzepine was lower than after treatment with cimetidine.