BACKGROUND Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, but the studies for the outcome after resection of ICC are rare. The aim of this study was to elucidate outcomes and prognostic factors of ICC in patients undergoing hepatic resection. METHODS A retrospective study was conducted with a total of 63 patients who underwent surgical resection with curative intent for ICC. We performed the survival analysis with preoperative and postoperative clinicopathologic factors according to the clinical outcome. RESULTS The cumulative 1-, 3-, and 5-year survival rates were 68.2, 50.5, and 31.8%, respectively. Univariate analysis revealed that patient's old age, high preoperative carbohydrate antigen 19-9 (CA19-9) level, major vessel invasion, T classification, lymph node metastasis, lymphatic invasion, perineural invasion, intrahepatic metastasis, and narrow resection margin were statistically significant. By multivariate analysis, patient's old age, high preoperative CA19-9 level, lymphatic invasion, and narrow resection margin were independent dismal prognostic factors. The preoperative CA19-9 level shows a significant correlation with some histopathologic factors including major vessel invasion, bile duct invasion, and perineural invasion. CONCLUSIONS Preoperative CA19-9 level was a valuable clinical factor for predicting histopathologic invasiveness as well as clinical outcome. An adequate resection margin was the only modifiable factor by a surgeon during hepatic resection for ICC.