Seven patients who had undergone a pneumonectomy for lung cancer developed a second tumor in the remaining lung after a mean time of 28.5 months and underwent a further resection. Preoperative evaluation was based on standard functional tests and on the "stair climbing test". Three patients were operated on using an extracorporeal oxygenator to work on a collapsed lung, three using standard anesthesiologic techniques, and one using high-frequency jet ventilation. There was no operative mortality. Complications occurred in two patients, requiring a temporary tracheostomy in one case. No patient required home oxygen supplementation. Four patients died of metastatic disease after 4, 8, 10, and 12 months, while two patients are alive and free of disease after 83 and 9 months, one is alive and free of symptoms but with a local recurrence after 29 months. Lung resection for bronchogenic carcinoma on a single lung can be safely performed provided that careful clinical judgment is used; long-term survival can be achieved with the resection of the new tumor.