Several reports have shown that prognostic factors of rectal cancer are pathological parameters such as lymph node metastases, tumour infiltration, perineural and venous infiltration, and clinical parameters such as tumour level, mobility of the tumour and number of quadrants involved. From 1979 to 1983, 208 patients were treated curatively for rectal cancer in Montpellier Cancer Institute. A multivariate analysis was done to evaluate prognostic factors of our population. Prognosis was influenced by lymph node metastases, preoperative radiotherapy, tumour infiltration and histological type. The role of preoperative radiotherapy in local control and in survival appeared highly significant. Our results confirm the importance of external beam irradiation in local recurrence and in survival as shown randomly in the EORTC prospective trial. The growing trend in sphincter-saving surgery should be associated with preoperative radiotherapy.