Between 1977 and 1985, 44 patients with osteosarcoma and pulmonary metastases were treated at Institut Curie and Marie-Lannelongue. Twenty patients were able to undergo operations according to our criteria. Of 17 patients who immediately after surgery were clinically and radiologically free of disease, six are alive with no evidence of disease and one suffered recurrent pulmonary disease; their 5-year survival is 37%. In 24 patients, various schemes for aggressive chemotherapy for measurable lung disease could be assessed. Only one patient had a complete response; there was one partial response, and three patients experienced stabilization of their disease for 6 to 8 months. Of five patients who had second line postoperative adjuvant chemotherapy, four relapsed within 2 months of stopping treatment. Surgical resection of lung metastases appears definitely to improve the outcome in osteosarcoma patients. Chemotherapy offers no advantage in treating bulk disease, but the prevention of new micrometastatic disease remains a possibility and should be assessed in randomised multicenter trials.