This study deals with the concept of caring for oneself and its relationship with the precept of self-knowledge in the Neoplatonists, as they were approached by Michel Foucault in The Hermeneutics of the Subject and The History of Sexuality volumes II and III. It points out the fact that according to Michel Foucault, the Neoplatonists remain broadly loyal to oneself care concept developed by Plato in his dialogue Alcibiades. In this sense, it highlights both the common elements and those that differentiate the Neoplatonists from Plato. It deals with the causes which developed significant changes in the Neoplatonists’ vision on the care for oneself. It emphasizes the importance of the concept of caring for oneself in Michel Foucault in the context of his interest for the complex relationship between the subject of knowledge and truth. Key words: care for oneself, self-knowledge, self-culture, truth, condition of spirituality, art to live, Plato, the Neoplatonists.