Segmental bilioenteric anastomosis procedures were performed on 22 patients with malignant hilar biliary obstructions. The majority of the bypasses were done to the segment 3 duct and a single anastomosis was performed in each patient. The operative mortality rate was 13.6% and morbidity, 27.3%. The biliary obstruction was completely relieved in 5 patients, partially but satisfactorily relieved in 11 patients, and not relieved in 3 patients. The mean survival was 8 months, and the median survival was 6 months. Late complications were seen in 42% of the patients, and these complications included cholangitis, liver failure, and duodenal obstruction. An analysis of the operative results with respect to the presence of right and left ductal system communication showed that when communication was absent, there was a greater incidence of unsuccessful relief of the biliary obstruction. When communication was present, the incidence of late cholangitis that involved the undrained side was greater.