Purpose: The purpose of this study was to identify prognostic factors of patients with intrahepatic cholangiocarcinoma (ICC) treated with resection and to investigate the effect of adjuvant chemotherapy (CT). Methods: Patients with ICC diagnosed between 2000 and 2015 treated at Hannover Medical School were included. Clinicopathologic characteristics were analyzed in univariate and multivariate analysis. In a matched pair survival analysis, patients with or without adjuvant CT were matched by these prognostic factors. Results: Two hundred and ten patients were included. Median survival was 28.7 months, 1-, 3-, and 5-year survival rates were 72.8%, 29.6%, and 14.1%, respectively. In multivariate analysis, lymph node involvement (p = 0.006, HR 1.84), larger tumor size (p = 0.013, HR 1.79), vascular invasion (p = 0.038, HR 1.70), and prolongation of prothrombin time (p < 0.001, HR 4.20) were significantly related to poor survival. Thirty-nine patients received adjuvant CT of which 60% had lymph node involvement. Each 25 patients with and without adjuvant CT were matched to the identified prognostic factors. The median survival of patients with adjuvant CT was 33.5 months, compared to 18 months in the control group (p = 0.002). The 1-, 3-, and 5-year survival rates were 96, 36, and 12%, compared to 60, 4, and 0% in non-treated patients. Conclusions: We identified several prognostic factors for patients with ICC treated with resection. Our data support the use of adjuvant CT in patients with ICC. The results of prospective randomized controlled studies will clarify the role of adjuvant CT in the future.