During the period between november 1964 and december 1982, 48 patients were operated upon for metastatic lesions of lung from previous or actual carcinomas and sarcomas elsewhere in the body. The most frequent sites of origin of the primary malignancy were colon, testis and breast. The usual approach was through a thoracotomy; bilateral lung metastases were removed with one-stage procedure through a median sternotomy in two patients. The operative mortality was 2%. Overall five-year survival was 26%, which was not influenced by tumor histology, disease-free interval, or extent of pulmonary excision. In view of these findings, conservative pulmonary resection of metastatic lesions is advocated, regardless of the tumor histology or the disease-free interval, when the following criteria are adhered to: primary site controlled or controllable; no extrapulmonary metastases demonstrable; good operative risk; no other effective means of treatment available.