To evaluate surgical results and the effect of adjuvant chemotherapy in cases of hilar cholangiocarcinoma, we retrospectively analyzed 27 consecutive patients who underwent surgical resection (eight bile duct resections, 18 bile duct resections plus hepatectomy, one hepatopancreaticoduodenectomy). There was no operative mortality, and the morbidity was 37%. Curative resection (R0 resection) was achieved in 20 (74%) patients. Overall survival at 3 and 5 years was 44% and 27%, significantly higher than that of 47 patients who did not undergo resection (3.5% and 0% at 3 and 5 years, p < 0.0001). Survival of patients with positive margins (R1/2 resection) was poor; there were no 5-year survivors. However, survival was better than that of patients who did not undergo resection (median survival: 22 vs 9 months, p = 0.0007). Univariate analysis identified lymph node metastasis as a negative prognostic factor (p = 0.043). Median survival of patients who underwent adjuvant chemotherapy was significantly longer than that of patients who did not (42 vs. 22 months, p = 0.0428). Resection should be considered as the first option for hilar cholangiocarcinoma. There appears to be a survival advantage even in patients with cancer-positive margins. Adjuvant chemotherapy may increase long-term survival.