The performance of sequential resections and the consideration of new lesions as second or third primary lung cancers remain controversial issues. Criteria to define these as new primary lesions depend upon a difference in histologic types, a prolonged interval between initial and second or third resections, and location in the contralateral lung or a different ipsilateral lobe. Ninety patients have undergone multiple resections for bronchogenic carcinoma from 1960 to December, 1983. There were 10 examples of synchronous lesions and the remaining 80 were metachronous with the longest interval between resections being 17 years, 4 months. The initial surgical procedure was pneumonectomy in 11, lobectomy in 43, sleeve lobectomy in eight, segmentectomy in 27, and carinal resection in one. At the second operation, the procedures were segmentectomy in 55, lobectomy in 11, completion lobectomy in six, and completion pneumonectomy in 15. Two patients had sternotomy with bilateral resections and one patient had a tracheal resection. At the third operation, the procedures were segmentectomy in seven, completion lobectomy in two, and completion pneumonectomy in two. In 20 patients undergoing the second procedure and three undergoing a third resection, a different cell type was identified. The perioperative mortality following the second operation was seven of 90 patients (8%) and there were no deaths in those patients undergoing three resections. The cumulative survival rate following second resection in 80 patients with metachronous tumors was 33% at 5 years and 20% at 10 years. These data support continued aggressive surgical approach to second and third primary lung cancers.