Endoscopic sclerotherapy (ES) and continuous propranolol (P) treatment have both been proposed as useful methods to prevent recurrent esophageal variceal bleeding. We report a prospective randomized trial in 65 patients with a previous history of endoscopically proven esophageal variceal bleeding. Patients were randomized by sealed envelopes stratified for Child's A and B groups to receive either endoscopic sclerotherapy (n = 31) or propranolol (n = 34). The dose of oral propranolol was based on a reduction of the resting pulse rate by 25%. Intravascular ethanolamine oleate was used for the endoscopic sclerotherapy in a 3-week schedule. The follow-up period ranged from 17 to 57 months (median: ES = 31; P = 28 months). There was no difference in the cumulative percentages of patients free of rebleeding from any source: esophageal and gastric varices, acute esophageal and gastric ulcers or erosions (ES = 37%; P = 16%). Also, there was no difference in the cumulative survival (ES = 69%; P = 54%). However, patients in the propranolol group had significantly more variceal rebleeding from the esophagus (n = 21) than did those in the sclerotherapy group (n = 9). The cumulative percentages of patients free of esophageal variceal rebleeding after inclusion were 67% in the endoscopic sclerotherapy group and 25% in the propranolol group (log-rank test, P less than 0.02). These differences indicated that sclerotherapy should be used in 29% of the propranolol patients who rebled. Based on these results we recommend elective sclerotherapy as long-term therapy for preventing rebleeding of esophageal varices.