Objective To evaluate the therapeutic efficacy of hyperthermia in combination with radiotherapy for regional recurrence of breast cancer. Methods Eighty-five lesions treated with local hyperthermia in combination with external irradiation were analysed retrospectively. Of the treated lesions,39 were previously irradiated. Mean radiation dose to previously un-irradiated area was 59.5 ?6.8 Gy(40-70 Gy), while a total dose of 43.0 ?12.4 Gy (12-74.4Gy) was given to previously irradiated tumors. Hyperthermia was administered once or twice a week. Average number of hyperthermia sessions was 4.5(2-9). Results The complete response rate(CR) was 90.0% one month after treatment.CR of 56.1%(23/41) for previously irradiated and 47.1%(16/34) for un-irradiated tumors were achieved respectively, with no significant difference between two groups although the radiation dose was significantly lower (43.0?12.4 Gy) for previously irradiated than that (59.5 ?6.8 Gy) for un-irradiat-ed. Comparing with the bulky/nodular tumor, the diffuse/multiple small nodular tumor showed higher CR rate 4 weeks after treatment, but it showed significantly lower local control rate 6 months after treatment. Conclusions Local control was improved when local hyperthermia combined with radiotherapy was administered in the treatment of locally recurrent breast cancer, especially the irradiation dose can be reduced for previously irradiated tumors. Diffuse/multiple small nodular tumors respond earlier than bulky/large nodular tumors. However, they tend to recur within the treatment fields.