The increasingly performed en bloc resection of liver and hilar tumor has contributed to the improvement of long-term survival in patients with hilar cholangiocarcinoma. Based on preoperative definition of operative strategy we tried to avoid any traumatization of the hilar region. Between September 1997 and September 2002, 82 patients with hilar cholangiocarcinoma were treated at our department. Three patients were excluded from any surgery. The resection rate was 75% (59 of 79); 79% (38 of 48) of en bloc resections of the hilar tumor and adjacent liver were formally curative. The hospital mortality was 7%. The 1- and 3-year survival rates of patients after explorative laparotomy, palliative and curative resection was 27 and 7%, 67 and 26%, 89 and 45% ( p<0.001), respectively. The 1- and 3-year survival rates of patients after en bloc resection were 78 and 49%, respectively. In patients with formally curative en bloc resection ( n=38), the 3-year survival rate was 63%; in patients with N0/R0 resection ( n=31) it was 71%. Lymph node involvement proved to be the only independent prognostic marker if patients who underwent hilar and en bloc resection were included in the multivariate analysis. The R situation was the only significant predictor for patients after en bloc resection. These data justify the extended diagnostic work-up and the principal liver resection in hilar cholangiocarcinoma.