From January 1987 to May 1988 sixteen pts with advanced squamous cell carcinoma of the head and neck received a combined treatment based on an alternation of chemotherapy and MFD--radiotherapy. The chemotherapy regimen consisted of CDDP 20 mg/m2 and 5-FU 200 mg/m2 i.v. push, from day 1 to day 5 during weeks 1, 5 and 9. Radiotherapy was administered in two courses of 32 Gy each (total dose 64 Gy), during weeks 2-3 and 6-7. Each course was given in 2 fractions per day, five days per week. All sixteen patients could be evaluated for toxicity and fifteen for response. The following were observed: 7 CR, 6 PR, 1 SD and 1 PD. The overall response rate was 86.6%. Toxicity was high; 43.7% of the patients developed grade III-IV mucositis. These results suggest that CDDP and 5-FU alternating with MFD-radiotherapy is feasible, although new, less toxic scheduling must be determined.