OBJECTIVE To evaluate the feasibility of induction chemotherapy followed by concomitant chemotherapy and hyperfractionated irradiation in locally advanced, inoperable head and neck cancer. METHODS A pilot study was undertaken comprising 3 cycles of cisplatinum (100 mg/m2, day 1) and 5-fluorouracil (1000 mg/m2 in continuous intravenous infusion over the first 120 h) followed by bifractionated radiotherapy applied to tumor/involved lymph nodes up to the dose of 74.4 Gy given in 2 fractions of 1.2 Gy daily for 5 days a week combined with concomitant weekly cisplatinum infusion (50 mg/m2). RESULTS Six patients were enrolled in the study. All of them completed the protocol therapy. Severe mucositis and myelotoxicity were the most common acute side effects observed in all and in 5 of the patients, respectively. Acute toxicity required interruption of concomitant chemotherapy in 5 cases and in 2 interruption of radiotherapy was necessary. Opioid analgesic parenteral therapy was administered in 4 patients. Three of them had to be hospitalized. One patient experienced cerebral stroke 1 day after the completion of therapy and died 7 days later. Due to high acute toxicity, patient accrual was terminated after 6 patients. At the mean follow-up of 17 months, 4 patients are alive, 3 of them are free of disease and in 1 local progression has been diagnosed. CONCLUSIONS High acute toxicity of induction cisplatinum and 5-fluorouracil followed by concomitant cisplatinum and hyperfractionated irradiation calls for less toxic treatment schedules in locally advanced inoperable head and neck cancer.