PURPOSE: Although considerable progress has been made in the management of hilar bile duct cancer, the long-term outlook for most patients remains poor. This study was conducted to analyze the long-term survival (more than 5 years) after resection for hilar bile duct cancer focusing on the clinicopathological factors influencing the outcome, and to develop an optimal strategy to achieve long-term survival after a resection. METHODS: A retrospective review was performed for 68 patients with hilar bile duct cancer who underwent surgical resection between 1988 and 2000. Survival rates and prognostic factors were assessed. Clinical and pathological factors of patients who survived more than 5 years were compared with patients whose survival was less than 5 years. Clinicopathological features characterizing the long-term survivors were also reviewed. RESULTS: Seventeen patients survived longer than 5 years after resection. The actual 5-year survival rate was 25.0%. Perineural invasion and resection margin were identified as independent prognostic factors. When prognostic factors were compared between the long-term and short-term survivors, tumor depth, TNM stage, perineural invasion, and resection margin showed a significant correlation with long- term survival. Long-term survivors had early TNM stages with negative lymph node metastasis and absence of perineural invasion. Six of 17 long-term survivors exhibited a positive resection margin. CONCLUSION: Long-term survivors showed characteristic features of early TNM stages with absence of perineural invasion and negative resection margin. As long-term survival can be expected even in patients with bad prognostic factors, aggressive surgical resection should be attempted for patients with resectable disease.