A cooperative randomized study was begun in August 1983 to compare a sequential program of induction chemotherapy followed by definitive treatment, arm A, with an alternation of chemotherapy and radiotherapy (three courses of 20 Gy in ten daily fractions), arm B. The same chemotherapy was used in both arms: 6 mg/m2, vinblastine, hour 0; 30 mg, bleomycin, hour 6; 200 mg, methotrexate, hours 24 to 26; 45 mg, leucovorin, hour 48. One hundred sixteen patients entered the study, 55 in arm A and 61 in arm B. The patients all had previously untreated squamous cell carcinoma of the head and neck (SCCHN). Forty-five patients had stage III and 71 had stage IV disease. The two arms were fully comparable. As of April 1986, 116 patients were evaluable for survival, while 112 were evaluable for toxicity and 105 for response. Response analysis shows that there were 14 complete responses (CR) and 11 partial responses (PR), for an overall response rate (ORR) of 52% in arm A, and 30 CRs and seven PRs, for an ORR of 64.9% in arm B. The difference in terms of CR between the two arms was statistically significant (P less than .03). Progression-free survival (PFS) was also statistically different, with an advantage for arm B (P less than .05), but without differences in overall survival. Arm B correlates with a significant increase in mucositis compared with arm A (P less than .001).