Preliminary results of an interdisciplinary study, conducted to investigate the efficacy of combined local hyperthermia and radiation/chemotherapy on carcinoma of head and neck, are reported. Upto now, eleven patients with recurrent squamous cell carcinoma of head and neck were treated, all of them had loco-regional recurrence, and 2 distant metastases in addition. 7 patients were pretreated by surgery and radiotherapy, 4 by radiotherapy only, and 6 by chemotherapy. Microwave-induced low-dose local hyperthermia was combined with radiotherapy (telecobalt 1100-2400 rad) 6 cases (group A) and with chemotherapy (bleomycin and cis-platin/bleomycin) in 5 patients (group B). Intratumoural temperatures between 43 and 45 degrees C were achieved for at least 30 minutes. The loco-regional efficacy of hyperthermia was assessed. 10/11 patients with 13 tumours could be evaluated, Group A: 3 CR, 4 PR, Group B: 1 PR, 4 MR and 1 NC.