Background and Aims: Despite resection being considered the treatment of choice for intrahepatic cholangiocarcinoma(ICC),percutaneous thermal ablation can be an alter-native treatment for patients unfit for surgery.Our aim was to compare long-term results of percutaneous sonographi-cally-guided radiofrequency ablation(RFA)with high-powered microwave ablation(MWSA)in treatment of ICC.Methods: Results of 71 ICC patients with 98 nodules treated with RFA(36 patients)or MWSA(35 patients)between January 2008 and June 2018 in 5 Interventional Ultrasound centers of South Italy were retrospectively reviewed.Cu-mulative overall survival curves were calculated with the Ka-plan-Meyer method and differences with the log-rank test.Eleven possible factors affecting survival were analyzed.Results: Overall survival of the entire series was 88％,65％,45％and 34％at 12,36,60 and 80 months,respec-tively.Patients treated with MWSA survived longer than pa-tients treated with RFA(p < 0.005).The MWSA group with ICC nodules ≤3 cm or nodules up to 4 cm survived longer than the RFA group(p < 0.0005).In patients with nodules>4 cm,no significant difference was found.Disease-free sur-vival and progression-free survival were better in the MWSA group compared to the RFA group(p < 0.005).Diameter of nodules and MWSA were independent factors predicting a better survival.No major complications were observed.Conclusions: MWSA is superior to RFA in treating ICC unfit for surgery,achieving better long-term survival in small(≤3 cm)ICC nodules as well as nodules up to 4 cm of neo-plastic tumors and should replace RFA.