Experience using accelerated hyperfractionation radiation therapy (twice-a-day) in the treatment of 60 patients with squamous cell carcinoma of the nasopharynx is presented. The local control rate at the primary sites was significantly improved statistically as compared with 58 patients with the same disease and stages treated by once daily (once-a-day) radiation therapy at the Massachusetts General Hospital (MGH) 5 years before twice-a-day radiation therapy. For the T1-2 lesions, the 5-year actuarial local control rates were 89% after twice-a-day and 55% after once-a-day radiation therapy, with a P value of 0.0021. For the T3-4 lesions, the corresponding rates were 77% and 45%, with a P value of 0.026. The improved local control rates occurred in patients with N2-3 disease and among male and female patients, and were reflected in patient survival. Although our study is not randomized, the improved local control and survival rates after twice-a-day radiation therapy are encouraging. However, the final answer will require a clinical randomized trial in the management of carcinoma of the nasopharynx.