Objective A randomized controlled trial was conducted to prospectively compare the therapeutic effectiveness of switching bipolar (SB) radiofrequency ablation (RFA) using cooled-wet electrodes and switching monopolar (SM) RFA using separable clustered (SC) electrodes in patients with hepatocellular carcinomas (HCCs). Materials and methods This prospective study was approved by our Institutional Review Board. Between April 2014 and January 2015, sixty-nine patients with 74 HCCs were randomly treated with RFA using either internally cooled-wet (ICW) electrodes in SB mode (SB-RFA, n = 36) or SC electrodes in SM mode (SM-RFA, n = 38). Technical parameters including the number of ablations, ablation time, volume, energy delivery, and complications were evaluated. Thereafter, 1-year and 2-year local tumor progression (LTP) free survival rates were compared between the two groups using the Kaplan-Meier method. Results In the SB-RFA group, less number of ablations were required (1.72±0.70 vs. 2.31±1.37, P = 0.039), the ablation time was shorter (10.9±3.9 vs.14.3±5.0 min, p = 0.004), and energy delivery was smaller (13.1±6.3 vs.23.4±12.8 kcal, p<0.001) compared to SM-RFA. Ablation volume was not significantly different between SB-RFA and SM-RFA groups (61.8±24.3 vs.54.9±23.7 cm3, p = 0.229). Technical failure occurred in one patient in the SM-RFA group, and major complications occurred in one patient in each group. The 1-year and 2-year LTP free survival rates were 93.9% and 84.3% in the SB-RFA group and 94.4% and 88.4% in the SM-RFA group (p = 0.687). Conclusion Both SB-RFA using ICW electrodes and SM-RFA using SC electrodes provided comparable LTP free survival rates although SB-RFA required less ablations and shorter ablation time.