Twelve breast cancer patients with locally advanced inoperable lesions were studied. Six cases had received chemotherapy, 6 had not. Most of the tumors were ulcerative lesions with an average size of 11.5 cm. The patients were treated with 43 degrees C hyperthermia once or twice a week together with radiation at a dose of 20-70 Gy. Six of them were also treated with concurrent chemotherapy. Two cases responded completely (17%) and 10 cases responded partially (83%). The result indicates that the combination of hyperthermia and radiation, with or without chemotherapy, might be a good treatment option for locally advanced inoperable breast cancer, especially for patients who have had failure or contraindication to chemotherapy. It is an effective treatment for palliation of local symptoms, showing a tendency to achieve local control of large, ulcerative advanced breast lesions especially when such treatment is followed by salvage surgery.