Twenty-seven patients with squamous cell carcinoma of the head and neck were treated with bleomycin 7.5 U/m2/day continuous infusion X 3 days (days 1-4, 8-11), followed by cyclophosphamide 300 mg/m2, methotrexate 30 mg/m2 and 5-fluorouracil 300 mg/m2 on days 5 and 12 (bleo-CMF). Treatment was repeated every 28 days. All but two had a performance status of 0-2 and all but 3 patients had received prior surgery, radiotherapy, and/or chemotherapy. Of 24 evaluable patients, 1 had a complete remission (1.9 months) and 4 had partial remissions (3.7, 3.9, 3.9, 4.1 months, respectively) for an overall response rate of 21%. If one excludes 7 patients with prior chemotherapy, the response rate is 5 of 17 (29%). All responders had received both radiotherapy and surgery. The median survival was 4.4 months for the responders and 3.5 months for the nonresponders. Marked hematologic toxicity occurred in eight patients, and contributed to the death of two. Severe pulmonary toxicity occurred in two patients and caused the death of one. Bleo-CMF did not produce a higher response rate than historical single-agent trials and caused significant toxicity. Furthermore, there was no important difference in the survival of responders and nonresponders.