A group of 60 patients with advanced head/neck cancer were treated with high-dose folinic acid (500 mg/m-2/week-1) plus 5-fluorouracil (400 mg/m-2/week-1 on day 1, and cisplatin (20 mg/m-2/week-1) 24 h after folinic acid infusion was completed. Out of 55 evaluable patients, 10 patients (18%) experienced a complete response with a mean duration of 11.4+ months, 25 patients had a partial response (45%) of 6.7+ months, 6 patients (11%) showed a stabilization of 4.8+ months, and 14 (25%) progressed. The overall response rate was 63.6% (95% confidence limits 56.5%-69.5%). Patients pretreated with radiotherapy had a 67% overall response rate, while those pretreated with chemotherapy showed a 54% overall response rate. All patients with cancer of the oropharynx had a major response, while patients with cancer of the oral cavity had the lowest response rate. The mean survival of patients who attained a complete response was 14.5+ months. Partial responders had a mean survival of 10.6+ months, while patients who progresses survived a mean of 3.6+ months. The treatment has been very well tolerated with few cases of grade 3 gastrointestinal toxicity. Grade 1-2 leukopenia was recorded in 64% of cases, grade 1-2 nausea/vomiting in 85%. In one case therapy was stopped because of persistent diarrhoea.