In a cooperative study by clinicians in three medical facilities, bumetanide was compared with furosemide in patients presenting with ascites, a complication of chronic liver disease. In an open, parallel, randomized trial, 43 patients received bumetanide and 16 patients received furosemide. They were treated for from one to 28 weeks. Weight loss and decrease in abdominal girth following diuretic action occurred in both groups but was statistically significant only in the bumetanide treated patients. Because of the small number of patients on furosemide, valid statistical analysis could not be obtained. No evidence of hepatic encephalopathy developed during this study, and only one patient on furosemide was discontinued as a result of severe electrolyte imbalance. Differences in changes of electrolytes and uric acid ere not statistically significant in the two groups. The majority of drug-related abnormalities were the result of the pharmacologic activity of the diuretic.