5-Fluorouracil (5-FU) and bleomycin (BLM) are active agents in head and neck squamous-cell cancer (H-N-scc). Less toxicity and an enhanced activity have been reported when these agents are administered by continuous infusion (CI), with or without a bolus of cisplatin (CDDP), another active agent. Thirty-three patients with recurrent and/or metastatic head and neck squamous cell carcinoma were treated with a combination regimen including CDDP (100 mg/m2) on day 1 plus BLM (15-mg bolus followed by 16 mg/m2/day by CI) and 5-FU (650 mg/m2/day by CI) on days 1-5 every 3 weeks. Thirty-one patients were evaluable for toxicity and response. The response rate (RR) was 15% (5 of 31), with one complete response (CR) and four partial responses (PRs), at a confidence interval of 95% (0-34%). Four of the five responders had not received previous radiotherapeutic treatment. Toxicity was deemed acceptable; nausea and vomiting and stomatitis were moderate. Only one patient had irreversible renal toxicity, after two cycles of chemotherapy. No symptomatic lung toxicity was observed. Good antitumour activity was noted for previously untreated disease (3 of 4; 75% RR). This combination of drugs proved to be inactive, however, in previously irradiated recurrent and/or metastatic H-N-scc (1 of 25; 4% RR). These results underscore the need to be extremely attentive to different patient populations when selecting therapeutic schedules and when analyzing reported results.