There are insufficient data on swallowing and the consequences of its dysfunction in patients with cancers of the oral cavity (OC) and oropharynx (OP) that are treated with primary surgery. The study attempts to explore the effect of important clinico-demographic variables on post-treatment swallowing and related quality of life (QOL) in post-surgical OC and OP cancer patients. Sixty-two consecutive OC and OP cancer patients completed the MD Anderson Dysphagia Inventory (MDADI) questionnaire. Mean scores were computed. Comparison of scores based on mean ranks were performed using Mann-Whitney U test or Kruskal-Wallis test. Level of significance was set at P ≤ 0.02. Adjustments were made for multiple comparisons. Significantly worse mean (SD) QOL scores were observed in late T-stage (T3/T4) versus early T-stage (T1/T2) patients for global domain, physical domain, functional domain and emotional domains [44.4 (21.9) vs. 78.7 (22.7) (P < 0.001); 50.0 (9.4) vs. 75.9 (16.3), (P < 0.0001); 57.8 (20.6) vs. 84.1 (16.7), (P < 0.001) and 55.2 (18.0) vs. 78.5 (16.3), (P < 0.001)], respectively. Patients undergoing reconstruction versus without reconstruction had worse QOL scores; 58.8 (26.9) versus 79.5 (22.8), (P < 0.01); 61.2 (15.1) versus 76.4 (17.5), (P = 0.002); 65.4 (20.5) versus 86.3 (15.9), (P < 0.0001) and 63.3 (18.8) versus 79.8 (16.3), (P < 0.01), respectively, for global, physical, functional and emotional domains. Advanced T-stage, reconstruction, younger age and base of tongue tumours have a negative impact on post-treatment swallow function and related QOL in these patients.