Objective: The objective of this study was to evaluate the treatment efficacy and overall survival (OS) of percutaneous ultrasound-guided thermal ablation by means of microwave ablation or radiofrequency ablation for intrahepatic cholangiocarcinoma (ICC). Methods: 18 patients with 25 ICC nodules underwent ultrasound-guided thermal ablation with curative intention. 8 patients were primary cases and 10 were recurrent cases after curative resection. The local treatment response, complications and survivals were analysed. Results: Complete ablation was achieved in 23 (92.0%, 23/25) nodules (diameter, 0.7-4.3 cm; mean, 2.5¡0.9 cm) and incomplete ablation was found in 2 (8.0%, 2/25) larger tumours (6.4 and 6.9 cm in diameter). No death associated with the treatment was found. The major complication rate was 5.5% (1/18). The follow-up periods ranged from 1.3 to 86.2 months (mean, 20.5¡26.3 months; median, 8.7 months). OS rates for all patients at 6, 12, 36 and 60 months were 66.7%, 36.3%, 30.3% and 30.3%, respectively. By univariate analysis, the patient source (primary or recurrent case) was found to be a significant prognostic factor for OS rates (p50.001). The patient source (p50.001) and the number of nodules (p50.038) were found to be significant prognostic factors for recurrence-free survival. OS rates for the primary ICC at 6, 12, 36 and 60 months were 87.5%, 75.0%, 62.5% and 62.5%, respectively. Conclusion: Percutaneous ultrasound-guided thermal ablation is a safe and effective therapeutic technique for ICC. Acceptable survival can be achieved in primary ICCs, whereas the prognosis of recurrent ICCs is relatively poor.