Primary lung cancer is the most frequently diagnosed malignancy in the world and the leading cause of death from cancer [1]. When the initial diagnosis is made, most cases are inoperable or the patients’ condition does not permit surgical interventions [2]. For patients with inoperable lung cancer, percutaneous radio-frequency thermal ablation (RFA) under CT guidance represents an alternative and minimally invasive treatment. It can also be applied in combination with radiation therapy and chemotherapy. We report three cases treated by percutaneous CT-guided RF ablation, from which two had post-operative recurrent tumor and one was inoperable.