In a prospective study performed between 1977 and 1985, 27 patients with cholangiocarcinoma at the confluence of the hepatic ducts underwent resection aiming at cure. Eleven patients underwent local excision and 16 underwent partial liver resection (extended right hepatic lobectomy in 12, left hepatic lobectomy in 3, and extended left hepatic lobectomy in 1). The 60-day hospital mortality rate was 7.4% (2 patients). None of 11 patients who underwent local excision and only 1 (5.5%) of 18 patients who had not undergone previous surgery, or preoperative biliary drainage, died in the hospital. The overall median and mean survival times for the 24 patients who left the hospital were 25 and 29 months, respectively (range, 5 to 80 months). Twenty patients died after a median survival of 22 months (mean, 25 months; range, 5 to 80 months). Four patients are alive and well at 45, 48, 51, and 54 months. Estimated (Kaplan-Meier) survival rates for all 27 patients at 1, 3, and 5 years were 70%, 26%, and 22%, respectively, with almost all patients dying of persistent or recurrent local disease. Survival time after hepatic resection was not statistically different from that after local excision of the lesion (p greater than 0.1). The difference in survival times between patients with histologic clearance and those with microscopically positive or close (less than 1 mm) resection margins was marginally significant statistically (p = 0.037). The quality of life was good. These results are in agreement with those of other studies employing treatment by excision and emphasize the need to assess all patients with hilar cholangiocarcinoma with a view to resection before the adoption of surgical bypass or palliative intubational procedures. However, further progress is unlikely to be made without significant advances in adjuvant therapy.