Many studies point to factors capable of increasing longevity but many questions regarding this subject were still not elucidated. The perceptions of the old aged themselves with respect to factors that contribute to longevity are important, allowing to identify each factor and its interactions with other variables promoting longevity. This article presents the results of an investigation about "the secret of longevity", according to old-aged themselves, analyzed through grounded theory. Thirty old-aged men, former railroad workers, were interviewed in the city of Botucatu (SP). The analysis of their discourse led to the conclusion that the perception of the factors can be grouped around progressively inclusive categories that culminate in the collective representation that longevity depends on the balance between negative life-destroying factors and healthy, life-generating and life-preserving factors. The lack of social and state control over these factors is generating a pessimistic view for the future.