Between 1973 and 1975 inclusively, 75 patients with squamous cell carcinoma of the oral cavity were seen in the Division of Radiation Oncology at Hôpital Notre-Dame. Of these, 10 patients not treated or incompletely treated were excluded from the results. Results are presented at four years for three modalities of treatment: 1) interstitial therapy: an ultimate local and regional control was obtained in 17 of the 19 patients treated (90 per cent); 2) combined therapy: this modality used with 21 patients, gave ultimate local and regional control of 71.3 per cent; 3) external radiotherapy: telecobalt therapy only was given to 25 patients, and the ultimate local and regional control rate was 52 per cent. The ultimate local/regional control of patients with neck involvement at diagnosis in 57 per cent vs 81 per cent in patients without neck disease. At four years 26 patients had died with disease and 46 per cent of these had distant metastasis.