To evaluate prophylactic injection sclerotherapy (EIS) for esophageal varices, a prospective randomized controlled trial was begun in 1993 by the Japanese Society for Portal Hypertension. 79 patients whom endoscopic findings suggested high risk of bleeding but who had no bleeding episode, were randomly allocated to the EIS group of 40 patients or non treated group of 39 patients. Patients were followed for 42 months to 89 months. Variceal hemorrhage occurred in 3 patients receiving EIS and 10 patients of the controls (p = 0.057). The survival curves (Kaplan-Meier) of both groups were similar (p= 0.61). We conclude that prophylactic sclerotherapy does not significantly reduce the risk of bleeding from esophageal varices and is not effective in improving survival.