Of 60 patients suffering from various stages of esophageal varices with no previously recorded bleeding, 30 underwent combined peri- and intravascular fiberscopic sclerotherapy in a prospective controlled study. Each of the two groups consisted of 22 men and 8 women with an average age of 49 years. The cause of portal hypertension in 58 patients was a morphologically proven cirrhosis of the liver, due mainly to alcoholism. Portal vein thrombosis was present in two patients. The severity of the liver disease was first evaluated in accordance with the PUGH modification of the CHILD classification. 53% of the patients in the control, and 56% in the treatment, group belonged to the prognostically favourable CHILD A category. The period of observation was at least 26 months, with a mean of 36 months. Sclerotherapy lowered the risk of bleeding to 13.3%; in the control group it was 30%. The mortality rate during the overall observation period was lowered significantly (p less than 0.05) by sclerotherapy to 5.9% in the CHILD A group as compared with 25% in the control group. The mortality rate of CHILD B and C patients was over 40% in the control group and an unequally large 70% in the treatment group. The most frequent cause of death was bleeding from esophageal varices in the control group and liver failure in the treatment group. Complications were seen in 20% and paralleled the severity of the esophageal varices. All complications responded to conservative treatment and no fatality was seen.