PURPOSE: This prospective multicenter study aimed to evaluate the efficacy and safety of percutaneous radiofrequency (RF) ablation for lung cancer. MATERIALS AND METHODS: From May 2008 to April 2012, 33 patients (26 men, 7 women; mean age 70.5 years) were enrolled. RF ablation was performed using an internally cooled or expandable multitined electrode. The primary endpoint was complete response (CR) determined using (18)F fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) performed 6 months after RF ablation. The secondary endpoint was the incidence and grade of adverse events (AEs) evaluated using the Common Toxicity Criteria for Adverse Events, version 3.0. RESULTS: All patients underwent RF ablation and had efficacy analyses evaluated; however, FDG-PET/CT images before RF ablation were not available for two patients. The CR rate was 68 % (21 of 31 patients). One patient had a grade 5 AE unrelated to RF ablation. Grade ≥3 AEs occurred in 12 % of patients. During the follow-up period (median 37 months; range 1-55 months), five patients developed local tumor progression and nine (29 %) died. Overall survival at 1, 2, and 3 years was 97, 82, and 74 %, respectively. CONCLUSION: Percutaneous RF ablation is a safe, feasible, and effective treatment for small malignant lung tumors.