Between August 1983 and September 1986 18 patients affected with osteosarcoma of the limbs in which the extent of the neoplasm would normally have required amputation were treated by two cycles of intra-arterial infusion of CDDP, associated with methotrexate at high doses administered i.v., followed by a hyperthermic-antiblastic perfusion confined to the affected limb with CDDP at high doses. At the end, the patients were administered two more cycles of methotrexate at high doses and CDDP intravenously. The immediate response, evaluated in radiological, clinical and histological terms, was such that in 11 patients it was possible to obtain satisfactory results with conservative treatment alone. None of the patients developed local recurrence.