Two hundred and fifty five patients undergoing treatment for oral cancer were studied. Tumour site, classification and treatment modality were recorded and an assessment of their ability to swallow was made postoperatively. Patients were graded into one of three groups depending on dietary consistency. Pre- and postoperative dental examinations were made and patients were weighted pre- and postoperatively. Postoperative functional problems are outlined. The results indicated that 21% of the sample reported difficulty with swallowing solid foods and 46% were limited to semi-solid or liquid diets postoperatively; 16% were unable to wear upper or lower dentures postoperatively and 15% of edentulous patients were able to wear an upper denture only; 65% of the patients who had surgery and radiotherapy were unable to regain their preoperative weight after 6 months. Patients with T1 tumours who did not progress to radiotherapy faired much better postoperatively and were more likely to return to normal diet and regain their preoperative weight.