In malignant bone and soft tissue tumors, lung is the most predilection site of metastasis and multiple pulmonary metastases is a poor prognostic factor. Aggressive treatment of pulmonary metastases may offer a chance of long term survival in selected patients whose primary tumors were controlled. We wanted to know the feasibility of pulmonary metastasectomy, whether it can prolong the survival. From Apr. 1989 to Dec. 1993, pulmonary metastasectomies were carried out for 20 patients, and followed up to Sept. 1994, with average follow-up period of 18.7(2-65) months. The primary malignant tumors were 8 in bone and 12 in soft tissues. Mean age was 27.5(12-70) years. Fifteen cases showed late metastasis after control of primary tumor(late metastasis group), and 5 cases showed pulmonary metastasis at first visit(initial stage III group). As a control we analyzed the survival of 24 cases of no treatment after pulmonary metastasis from bone or soft tissue sarcoma, during the same period of investigation. At final follow-up, in late metastasis group, 4 cases were in no evidence of disease (NED), 4 alive with disease (AWD) and 7 dead of disease (DOD). Tumor free interval (TFI) of NED and AWD was averaged 30 months, and for DOD 9.8 months. Five among 11 cases (45%) of multiple lung metastases and 3 among 4 cases (75%) of single metastasis were alive. In initial stage III group, 1 case was in NED, 1 AWD and 3 DOD. For late metastasis group, Kaplan-Meier's 5-year estimated survival rate from the first metastasectomy was 37.4%. The median survival period of 15 cases was 44 months. For initial stage III group, Kaplan-Meier's 9 months estimated survival rate was 40%. Median survival period was 8 months. Twenty four cases of no treatment cases died within 14 months from diagnosis of pulmonary metastasis. Their median survival period was 6 months. Pulmonary metastasectomy appears to prolong survival and occupies an important mode of treatment for late pulmonary metastases in malignant bone and soft tissue tumor patients. In the cases of initial stage III, more cases and follow up period are needed to have a conclusion.