Twelve consecutive unselected patients (aged 6 to 18 years) with osteogenic sarcoma underwent 19 thoracotomies for resection of pulmonary metastases. Wedge excisions of 41 metastatic nodules, one bilobectomy, and one pneumonectomy were performed. Six patients each required one thoracotomy, five patients underwent two thoracotomies, and one patient required three. Serious surgical complications were limited to one patient who required reoperation for closure of a bronchopleural fistula following bilobectomy. Initial pulmonary metastasis occurred 9 months (mean) after amputation (range 1 to 21 months). Complete excision of all identifiable metastatic tumor was possible in 17 of 19 thoracotomies. All patients received intensive cyclical chemotherapy after initial definitive amputation, after thoracotomy, or both. Tumor doubling time (TDT) during chemotherapy (mean 74 days) was significantly prolonged (p = 0.017) compared to TDT during intervals of no therapy (mean 22 days). Five patients received pulmonary radiotherapy prior to thoracotomy and five after thoracotomy. Four patients died during the observation period, having survived 10 to 30 months after amputation. Two patients are alive with known extrapulmonary metastases. Six patients are free of disease. The survival rate is 91.7 percent 1 year after amputation, 82.5 percent at 2 years, and 57.8 percent at 3 years. These results suggest improved survival when aggressive surgical resections of pulmonary metastases are combined with chemotherapy and radiotherapy. Thoracic surgical procedures in this group of patients are safe and associated with a low incidence of complications despite the potentially increased risks owing to antecedent chemotherapy and pulmonary irradiation.