The current treatment of bone and soft tissue sarcomas consists of a multimodality approach based on the combination of surgery, radiotherapy and, more rarely, chemotherapy. Since local recurrence is an important cause of failure and morbidity, new treatment modalities such as hyperthermia, have been proposed to try to overcome this problem. July, 1982, to June, 1993, twelve patients (15 lesions) with recurrent or locally advanced sarcoma, were treated at the Department of Radiation Oncology, S. Chiara Hospital-Trento (Italy) with irradiation and hyperthermia. Radiation therapy was delivered with different techniques using palliative or radical doses (24-70 Gy) and different fractionation schedules. Local microwave hyperthermia was given in 2-9 sessions (mean 4.7). Eight (53.3%) complete responses and 4 (26.6%) partial responses were observed. Three lesions recurred at 11, 13, and 30 months; 5-year actuarial local control was 25.4 +/- 13.4%. Actuarial 5-year overall survival was 49.5 +/- 16.4%. Toxicity was mild: two superficial necroses, spontaneously healed after few months, were observed; local pain during hyperthermic treatment was recorded in 15% of sessions. Lesion volume and total radiation dose appeared to be correlated with the response. In our experience, the combination of radiotherapy and hyperthermia seems to be a valuable therapeutic approach in the treatment of locally advanced or recurrent sarcomas.