Forty-one patients admitted with first episode of bleeding from esophageal varices were enrolled in a trial of the efficacy of oral propranolol to prevent rebleeding during the course of endoscopic sclerotherapy until obliteration. Single-blind randomization to sclerotherapy alone or with propranolol was used. At monthly endoscopy the varices were injected with 1% Aethoxysclerol until obliteration. If bleeding recurred, additional sclerotherapy was given. There was no intergroup difference in time to eradication of varices (8.1 vs. 7.7 months). The cumulative number of bleedings from varices and from distal esophageal ulcerations was identical in the two study groups. Five patients in the control group but only one in the propranolol group died of bleeding in the study period, a difference of only borderline significance (chi 2 = 4.08, df = 1). There were no specific side effects of propranolol. Thus propranolol did not significantly reduce the frequency of rebleeding until variceal obliteration, but could have had some influence on the gravity of rebleeding.