The purpose of this study was to evaluate the 5-year results for a phase II trial of hyperfractionated radiotherapy (RT) and concurrent daily cisplatin chemotherapy. Between August 1994 and December 1999, 63 patients with stage IIIA and stage IIIB non-small-cell lung cancer were treated with RT to a dose of 69.6 Gy at 1.2 Gy twice daily with daily cisplatin at 6 mg/m2. Thirty-seven patients elected to receive consolidation carboplatin and paclitaxel chemotherapy. Recurrence and survival outcomes were evaluated by Kaplan-Meier analysis. Acute and late side effects were scored by the Radiation Therapy Oncology Group (RTOG) grading system. Radiographic complete or partial tumor response was achieved in 34 of 63 (54%) of cases. Median absolute survival was 20.1 months. Median time to local recurrence and distant metastases were 10.6 and 8.6 months, respectively. Overall survival rates were 57%, 35%, and 23% at 1, 3, and 5 years, respectively. Survival was significantly greater for patients receiving consolidation chemotherapy (50% versus 20% at 3 years). Only 5 patients (7%) experienced Grade 3 or 4 esophagitis. There were 16 cases of Grade 1 or 2 pneumonitis; steroid therapy resolved symptoms in 9 patients. This regimen of hyperfractionated RT and chemotherapy achieved significant response, and 5-year survival rates with acceptable toxicity. Copyright © 2005 by Lippincott Williams & Wilkins.