Over a period of six years, esophageal varices (stage III or IV) were endoscopically diagnosed in 49 patients with confirmed liver cirrhosis and no previous bleeding. Prophylactic sclerotherapy of the esophageal varices was performed in 25 patients, while 24 were treated conservatively (control group). The groups were comparable as to duration, cause and severity of the cirrhosis, but differed in sex distribution. The patients had been followed for at least two, maximally seven, years (median 44 months). Only five bleedings occurred in the prophylactic sclerotherapy group, 15 in the control group during the entire observation period. Among the control group eight patients died due to bleeding, compared to only one in the sclerotherapy group; but there were eight deaths in the control group, 13 in the sclerotherapy group from other complications of liver cirrhosis. Survival rate was higher in the sclerotherapy group, especially in the first year and with alcoholic cirrhosis. There were no serious complications from the sclerotherapy. It is concluded that prophylactic sclerotherapy clearly reduces the number of bleedings from varices, but improvement in prognosis is relatively short.