A Phase I / II study of docetaxel (DOC) and cisplatin (CDDP) combination therapy was conducted. The respective recommended dose (RD) in a phase I study was DOC 60 mg/m(2) and CDDP 80 mg/m(2). We performed a multicenter phase II study to assess the antitumor activity and toxicity of this RD. Patients with recurrent or unresectable squamous cell carcinoma of the head and neck were eligible. For inclusion in this study, patients were required to be >or=20<70 years of age with a Performance Status of 0 to 2. Adequate bone marrow as well as adequate renal and liver function were required. We assessed 22 patients, 13 of whom were enrolled in the phase II study, and 9 patients in phase I were given the RD. Grade 3 or higher neutropenia occurred in 12 patients (55%). There was no episode of febrile neutropenia of more than 3 days or grade 4 neutropenia of more than 3 days receiving G-CSF. Nausea was the most frequent toxicity, but only one patient experienced vomiting of more than grade 3. Pneumonia (grade 3), thrombocytopenia (grade 4) and emphysema (grade 2) were observed. No one achieved a complete response (CR) and 5 achieved a partial response (PR), for an overall response rate of 22.7% (5/22). Stable disease (SD) was seen in 11 and progressive disease (PD) in 6. In 21 of 22 patients, a relapse occurred despite previous treatment. For this population, the response rate was 19.0% (4/21).