From 1975 to 1990, eighty-nine primary tumors of the thoracic skeleton; ribs, sternum, scapula, clavicle, and thoracic spine, were treated. Forty-four tumors (49%) were benign lesions. Forty-five tumors were malignant and were proportionately distributed amongst the five sites. The most common malignancies were Ewing's sarcomas, chondrosarcomas, plasmacytomas, osteogenic sarcomas, and lymphomas. All patients with Ewing's sarcomas were treated with combination chemotherapy, surgical resection, and radiation therapy for those with residual disease after surgery. Only one patient has died of disease. Patients with primary chondrosarcomas were treated by surgery alone and all are free of disease or have died without disease. Patients with solitary plasmacytomas or primary lymphomas of bone were treated with radiation therapy initially. Half the patients developed systemic disease. The patients with osteogenic sarcomas included several with radiation induced lesions and Paget's osteosarcoma and all but one died of disease.