In order to define the main diseases of the elderly and a possible changes of mortality causes at Hospital General of Mexico, SSA, the authors studied 586 autopsy reports of individuals over sixty years old, deceased between 1960 and 1965 and of 625 individuals of similar characteristics deceased between 1981 and 1985. The analysis of diseases showed qualitative and quantitative changes in the ten principal causes of death at each period: some of the most frequent diseases in the 60's, for instance, amebiasis, were not included among the then principal causes of death in the 80's. On the other hand, malignant neoplasms persisted as one of the principal death causes in both periods, but the most frequent carcinoma in the 60's, gastric carcinoma, was substituted in the 80's by bronchogenic carcinoma. This study suggests that great technical and sanitary interventions are necessary to promote health of third age persons, an increasing but poorly protected population in our country.