To determine the efficacy, feasibility, and toxicity of treated with platinum-based chemoradiotherapy for oropharyngeal carcinoma. A retrospective survey of 91 patients who underwent platinum-based chemotherapy and radiotherapy for oropharyngeal cancer at Aichi Cancer Center Hospital between 1971 and 2003. The radiotherapy dose ranged from 50 to 74Gy (median, 66Gy). Nine patients who had a tumor in the base of the tongue were also treated with arterial infusion chemotherapy. At a median follow-up of 63months (range, 2-190 months), 26 (29%) patients developed recurrence. Five patients (5%) developed distant metastases. The 5-year overall survival was 66%, and the relapse-free survival was 51.6%. The 5-year local control rate was 79%. The 5-year local control rate for each subsite was: anterior wall, 90%; lateral wall, 80%; posterior wall, 67%; and superior wall, 64%. The 5-year overall survival was 85% for stage I-II and 62% for stage III-IV. Two patients developed grade 3 (mandibular bone necrosis) or 4 (laryngeal edema) late toxicities. No acute or late grade 5 toxicities were observed. In this study, platinum-based chemoradiotherapy provided good local control for oropharyngeal carcinoma. Although acute and late toxicities occurred, they were considered tolerable.