We performed endoscopic injection sclerotherapy (EIS) in the treatment of 37 patients with bleeding esophageal varices due to unresectable hepatocellular carcinoma (HCC). The results were compared with those in another 33 HCC patients treated only conservatively, without EIS, during the same period. A majority of both groups died within 3 weeks after treatment. Comparing the two groups, there was no significant difference in fatal bleeding (66% vs 75%), but significantly fewer of the EIS patients died of the index hemorrhage (43% vs. 83%; p less than 0.01). Also, in the absence of portal vein thrombosis, EIS significantly reduced the risk of fatal bleeding (31% vs. 73%; p less than 0.25). The mean days of survival were 32 +/- 15 (range, 2 to 320) in the EIS group and 10 +/- 14 (range, 2 to 270) in the compared group (p less than 0.001). We conclude that EIS provides temporary control of acute esophageal variceal bleeding in patients with unresectable HCC. The major factors contributing to EIS failure are the lethal propensity of the underlying disease and portal vein thrombosis.