We report 3 patients with lung cancer complicated with interstitial pneumonia who were treated by percutaneous computed tomography-guided radiofrequency ablation. Patient 1 recovered from a pneumothorax without chest drainage. Patient 2 presented with a progressive pneumothorax after discharge from the hospital and required readmission for air drainage. In patient 3, the pneumothorax did not improve by chest drainage and pleurodesis, and the patient died of acute exacerbation of interstitial pneumonia. Radiofrequency ablation of intractable lung cancer with complicating interstitial pneumonia requires careful consideration because a progressive pneumothorax may require surgical intervention or result in acute exacerbation of interstitial pneumonia.