Background. Hilar resection, especially in combination with liver resection, results in substantial morbidity and mortality, which clearly influences the overall outcome. In the present study, patients who underwent resection of a proximal bile duct tumor were analyzed with the aim of identifying risk factors for morbidity and mortality. Methods. Between 1983 and 1998, 112 consecutive patients underwent a focal resection, which in 32 patients was combined with a hemihepatectomy (11 extended resections). Eighty-four percent of the patients underwent preoperative (endoscopic) drainage. For evaluation of different treatment strategies during the study, the period was divided in three 5-year intervals. Results. Postoperative complications occurred in 65% of the patients. The overall hospital mortality was 15 % for focal resections and 25 % for hemihepatectomies. There was a significantly lower morbidity and no mortality after hilar resection during the last 5 years. A higher Bismuth classification showed significant correlation with postoperative morbidity. Extended liver resections and vascular resections and a preoperative albumin level below 35 g/L were found to be significant predictors of increased mortality in univariate analysis. Conclusions. The overall morbidity and mortality rate in this series is higher than most recently published series. More (extended) fiver resections resulted in an increased rate of microscopic tumor-free resections, at the cost of higher hospital morbidity and mortality. Improved preoperative work-ups will result in a selection of patients who might benefit from these extensive resections.