To evaluate the efficacy of radiofrequency (RF) ablation for treatment of unresectable intrahepatic cholangiocarcinoma (ICC) and to explore the impact of prognostic variables on outcomes. From 2000-2010, 17 patients with 26 ICCs underwent RF ablation at a single institution. None of the patients were surgery candidates. Seven patients had 15 primary ICCs, and 10 patients had 11 recurrent ICCs. The median largest diameter was 4.4 cm (range 2.1-6.8 cm). A percutaneous approach was used in 15 patients, and an open approach was used in 2 patients. Early tumor necrosis, recurrence-free survival, and overall survival were analyzed. Univariate analysis was performed to evaluate 12 clinicopathologic and treatment-related variables associated with recurrence-free survival and overall survival. Early tumor necrosis was 96.2% (25 of 26 tumors). The median follow-up period after RF ablation was 29 months. The median recurrence-free survival and overall survival were 17 months and 33 months. The 1-year, 3-year, and 5-year survival rates were 84.6%, 43.3%, and 28.9%, with an overall complication rate of 3.6% (1 of 28 sessions). Three variables were found to be closely associated with recurrence-free survival: lymph node metastases (P = .023), tumor differentiation (P = .034), and tumor number (P = .035). The only variable significantly associated with overall survival was tumor differentiation (P = .033). Preliminary results showed that RF ablation may be an effective treatment for ICC because it achieved an acceptable survival rate in a small population. Prognostic factors might allow better patient selection and outcomes.