After excluding terminally all patients, we evaluated a total of 718 patients treated with endoscopic injection sclerotherapy. They involved 350 episodes of acute hemorrhage and 368 prophylactic procedures in patients with risky varices. The 1-year cumulative survival rate was significantly lower in the acute hemorrhage group than in the prophylactic group (P < 0.05). The difference in survival between the two groups was primarily due to the number of deaths in the first 2 months after sclerotherapy (20.1% vs 0.8%, P < 0.0005). Improvements in the sclerotherapy technique significantly reduced the number of deaths from bleeding (9.3% vs 3.4%, P < 0.05), but not those from liver failure following variceal hemorrhage. Prophylactic EIS is advantageous in the treatment of esophageal varices, i.e. it may prevent deaths from liver failure attributed to variceal hemorrhages. The present study shows that preliminary prevention of variceal hemorrhage provides favorable hemostatic efficacy in patients with risky varices.