The objective of this study was to analyze the influence of changes in the treatment on the prognosis of patients treated over 44 years in a single institution. The 5-decade trends in treatment approach and 5-year survival of 3267 patients treated between 1953 and 1997 were analyzed. An increase was observed in primary surgical treatment and its association with radiotherapy. In the 1950s, 29.1% of the patients were treated by surgery, 54.5% by radiotherapy and 16.4% by combined treatment; in the 1990s, these proportions were 39.7, 9.7 and 50.6%, respectively (P<0.001). There was a significant increase in the 5-year survival rates from 28.7% for patients treated in the 1950s to 43.2% in the 1990s (P<0.001). The changes in treatment approach for oral and oropharyngeal cancer over the last 5 decades, with an increase of surgical treatment and its combination with radiotherapy significantly improved the survival rates.