From January 1976 to December 1986, 199 patients with oropharyngeal cancer were submitted to definitive radiotherapy. Survival and local control were analyzed and related to different parameters--i.e, T and N categories, histopathologic grading, tumor location, patients age, and radiation dose. Fifty-six per cent of patients (111/199) died from neoplastic disease within 5 years. Local progression, recurrence or metastases were observed in 149 cases (75%). Ninety-three per cent of first failures (138/149) were related to residual disease or to locoregional relapse while distant metastases occurred in 14 patients only. The majority of locoregional failures (94%) appeared within 2 years, with a mean disease-free interval of 8 months. Tumor recurrence in the primary location was observed to be the first cause of failure in 78% of relapsed patients; moreover, it was the sole cause of failure in half of the unfavorable events. On the contrary, nodal relapse appeared in 38% of treatment failures and in 12% only it was the sole cause of failure. Overall and disease-free survival were observed to depend mainly on T and N categories, while histopathologic grading was seen to affect only early response rate. No significant differences were observed depending on tumor site and patients age. Local control rates depended on total radiation dose, but the difference between low dose (NSD less than 1700) and high dose (NSD greater than 1700) was significant only for T1 and T2 patients.