The feasibility of chemotherapy of three courses of cis-platin and 120-h 5-fluorouracil (5-FU) infusion after definitive surgery, followed by standard radiotherapy, in patients with resectable locally advanced head and neck cancer was carried out in Radiation Therapy Oncology Group (RTOG). Seventy-nine percent of the patients had stage IV cancer, 65% of the tumors were moderately differentiated, and primary sites were 38% oropharynx and 28% larynx. Toxicity to chemotherapy was acceptable, with no life-threatening side effects. Nausea and vomiting were the most common side effects (78%) and were severe in 26%; 30% of patients experienced had leukopenia, 22% had anemia, 13% had thrombocytopenia, and 9% had renal impairment--all of which were mild and reversible. In six patients, chemotherapy was not given for medical conditions or because of patient refusal. Of 23 patients started on cis-platin and 5-FU postsurgery, 18 (78%) completed all three courses. Ninety-six percent of the patients finished adequate radiotherapy according to the protocol. With minimum follow-up of 24 months, 62% of the patients were alive. Of the expired patients, 5 died from other causes, without evidence of recurrence at the time of their death. It is our conclusion that chemotherapy with cis-platin and 5-FU infusion following definitive surgery is feasible on the group level, and a Phase III trial comparing this combined modality therapy to standard treatment of surgery and post-operative radiotherapy is underway by the Head and Neck Cancer Intergroup.