Forty consecutive cases of carcinoma of the oropharynx were treated by irradiation from 1973 through 1987. The overall five-year survival rate calculated by the Kaplan-Meier method was 21%. Data were also analyzed retrospectively to investigate the factors associated with prognosis. The following results were obtained. (1) The results of re-irradiation as salvage treatment were poor. (2) Irradiation to neck lymph node metastases was not particularly effective, especially under 50 Gy. (3) Stage T2(-4) primary tumors were difficult to control with irradiation of 50 Gy.