Many scholars suggest that one of the main differences between Xenophon’s and Plato’s portrayals of Socrates is in their emphases on the self-control the self-knowledge respectively. The aim of the paper is to examine the role the self-knowledge plays in Xenophon’s Memorabilia. In its first part Xenophon’s conception of the self-knowledge is analysed. Then it tries to answer the question whether the self-knowledge requires any preconditions. The last part is focused on the possible obstacles precluding the self-knowledge.