Postoperative survival of multiple lung cancer patients were analyzed according to three groups of two metachronous groups (resection-resection, resection-medical or radiological treatment) and a synchronous group (resection at the same time). The metachronous groups had better 5 year survival rates than the synchronous group when they are compared from the first resection. But there was no significant difference between the three groups when the survival was compared from the time of second cancer, though the group of the second operation for the metachronous double cancers was the best in survival.