Background Liver resection is the only potential curative treatment for hilar cholangiocarcinoma. In this article, we evaluate mortality, survival, prognostic factors, and changes in surgical approach during the last two decades at a Western hepato-biliary center. Methods Fifty-one patients undergoing liver resections constitute the study population. Patients undergoing palliative procedures were considered as a control group for comparison to the resected group. After 1997, a more aggressive surgical approach was applied that is based on the experience of Japanese surgeons. Results Curative resections were achieved in 37 (72.5%) patients, and R1 resections were performed in 14 (27.5%). The overall 3- and 5-year survival rates were 47.3 and 34.1%, respectively. The 3- and 5-year survival rates were 38 and 19% in the R1 resection group, and 15% and 0 in the non-resected group, respectively. Univariate analysis revealed that lymph node and perineural invasion, R1 resection, and a bilirubin level >10 mg/dl affected long-term survival. Multivariate analysis showed that only perineural invasion was significant in affecting long-term survival. Univariate analysis showed that the mean preoperative bilirubin levels and mean blood transfusion were related to the mortality rate. The resectability rate significantly increased from 25 to 75.6% after 1997 following implementation of the new surgical approach. Conclusions An aggressive surgical approach increases the resectability rate and may improve long-term survival even after R1 resection. Severe hyperbilirubinemia should be preoperatively drained, possibly by the percutaneous approach.