We have performed pulmonary metastasectomy on 97 patients with various malignant tumors. We analyzed the outcome of surgical treatment and prognostic factors. Survival of patients undergoing metastasectomy was significantly different according to the type of malignant tumor. The patients with carcinomas had a good survival when they had 3 years or longer disease free interval (DFI) and no other lesion except the lungs. Those with sarcomas were good survivors, who had a solitary pulmonary lesion, 1 years or longer DFI, and had no symptom originating from pulmonary metastases. Survival of patients with germ cell tumors was significantly superior to other 2 types, and factors such as an existence of extra-pulmonary metastatic lesions, respiratory symptoms and a length of DFI had no impact on the chance of their survival. These results suggest that we should decide the indication for metastasectomy on patients according to their types of malignant tumor.