Background: Radiofrequency ablation (RFA) has been increasingly utilized as a non-surgical treatment option for patients with primary and metastatic lung tumors. We performed the present systematic review to assess the safety and efficacy of RFA. Methods: Searches for all relevant studies prior to November 2006 were performed on six databases. Two reviewers independently appraised each study using predetermined criteria. Clinical effectiveness was synthesized through a narrative review, with full tabulation of results of all included studies. Results: A total of 17 of the most recent updates from each institution were included for appraisal and data extraction. All were case series and were classified as level-4 evidence. The mean number of lesions treated ranged from 1 to 2.8, and the mean size ranged from 1.7 cm to 5.2 cm. The overall procedure-related morbidity rate ranged from 15.2% to 55.6% and mortality from 0% to 5.6%. The most commonly reported complication was pneumothorax (4.5-61.1%). Most pneumothoraces were self-limiting and only 3.3-38.9% (median = 11%) required chest drain insertion. The local recurrence of tumors at the site of RFA ranged from 3% to 38.1% (median = 11.2%). The median progression-free interval ranged from 15 months to 26.7 months (median = 21 months), and 1-, 2- and 3-year survival rates were 63-85%, 55-65% and 15-46%, respectively. Conclusions: Only observational studies were available for evaluation, which demonstrated some promising safety profiles of RFA.