352 Background: Although several studies have reported on actuarial survival outcomes following resection of hilar cholangiocarcinoma, the characteristics of patients who actually reached the 5-year milestone have not been adequately described. Methods: Patients who underwent resection for hilar cholangiocarcinoma from 2000-2015 in 10 US academic institutions participating in the Extrahepatic Biliary Malignancy Consortium were analyzed. Patients alive at last encounter with less than 5 years of follow-up were excluded. The clinicopathologic characteristics, perioperative, and long-term outcomes of actual 5-yr survivors and of patients who died within 5 years were compared. Results: Of 328 patients explored, 257 (78%) underwent curative resection and had an actuarial 5-year survival of 17%. After excluding 63 survivors with < 5 years follow-up, 194 patients were further classified as 5-year survivors (n = 23, 12%) and non-5-yr survivors. None of the 5-yr survivors had preoperative systemic biliary sepsis, portal vein embolization, T3 tumors with unilateral portal vein or hepatic artery invasion, or T4 tumors necessitating main portal vein or hepatic artery resection. However, actual 5-year survival was still achieved in the setting of bile duct resection only, R1 margins, poor differentiation, lymphovascular or perineural invasion, nodal metastasis, intraoperative blood transfusion, and serious postoperative complications. Five-year survival did not equal cure, as five 5-year survivors experienced disease recurrence, 2 before and 3 after the 5-year mark. There were ten actual 7-year survivors and four actual 10-year survivors. Conclusions: Although nodal metastasis, poor differentiation, and R1 margins are established predictors of poor outcome for hilar cholangiocarcinoma, the mere presence of these factors does not preclude patients from achieving a 5-year survival. In contrast, preoperative biliary sepsis, T3 or T4 stage, and the necessity for vascular resection and reconstruction appear to be prohibitive in reaching the 5-year milestone. This information can be utilized in the perioperative counseling of patients with this challenging malignancy.