Among 108 cases of endoscopic injection sclerotherapy (EIS) performed from January 1984 through September 1989, post-EIS variceal bleeding occurred in 38 case (35%). Death was significantly more frequent among the post-EIS bleeders than non-bleeders (55% v. 27%). Background factors were analyzed for failure to prevent bleeding. The curve of the cumulative non-bleeding rate following emergency EIS (21 cases) was significantly lower (P less than 0.01) than that following elective EIS (22 cases), and there was more frequent rebleeding (13/21 v. 7/22) within a shorter mean period of time (4.9 months v. 14.1 months) in the former; association of hepatocellular carcinoma was also more frequent (13/21 v. 3/22). Continuation of drinking showed no difference between post-EIS bleeders (5/38) and non-bleeders (9/70). After complete variceal eradication the curve of the cumulative non-bleeding rate was significantly higher than after incomplete eradication (P less than 0.001). Following prophylactic EIS (65 cases) there was significantly less frequent bleeding (P less than 0.01) than following EIS performed after variceal rupture (43 cases). The risk of variceal bleeding after EIS can be minimized by complete eradication of varices at the initial EIS. Prophylactic EIS was suggested to contribute to reducing the frequency of post-EIS bleeding.