[en] Purpose: The biological rationale for combining locoregional hyperthermia (HT) with cisplatin (CDDP) is the potentiating effect of HT on CDDP uptake and cytotoxicity. Feasibility, toxicity, and preliminary results of a clinical trial of weekly loco-regional HT in combination with cisplatin are described in this article. Methods and Materials: Patients with a previously irradiated unresectable local recurrent cervical carcinoma or locally advanced bladder carcinoma were treated with weekly cycles of locoregional HT (70 MHz four antenna phased array system) for 1 h and CDDP 50 mg/m² IV for a maximum of 12 courses. Results: Fourteen patients, 10 patients with recurrent cervical carcinoma and 4 with a locally advanced bladder carcinoma, were entered in this study. A total of 100 cycles were given. Overall toxicity was acceptable; Grade 3 (WHO) toxicity (gastrointestinal, hematological, and neurotoxicity) was observed in 5 out of 14 patients. No Grade 4 toxicity was seen. Subcutaneously fatty necrosis due to HT occurred in 11% of the cycles, while two patients developed skin burns. Two out of 10 patients with recurrent cervical carcinoma were not evaluable for response. Four out of eight evaluable cervical carcinoma patients responded (two pathologic complete responses, one pathologic confirmed partial response, one partial response): response rate 50% (95% confidence interval 15.7-84.3%). Salvage surgery became possible in three out of four responding patients, whose tumors were previously considered unresectable. Two out of the four evaluable patients with locally advanced bladder carcinoma responded (two partial responses). Conclusions: Weekly loco-regional HT and CDDP 50 mg/m²/week for a maximum of 12 courses is feasible with an acceptable toxicity, which seems not to be enhanced by the addition of loco-regional HT. The encouraging preliminary results of this treatment schedule warrant further study, especially in patients with previously irradiated recurrent cervical carcinomas