Radiofrequency ablation can be used to treat primary or metastatic pulmonary tumors when surgery is not indicated or involves high risk. Although this technique is less invasive than surgical resection, it is not free of risk for complications and adverse events, especially when it is used in patients with serious respiratory disease in whom comorbidity is common. We report 2 cases of serious complications. One was an intractable air leak that led to death. The other was a large hemothorax that was brought under control in the radiology procedure room. We review the literature on this technique as well as recommendations that contribute to making it as safe as possible.