The article is devoted to the analysis of the role of unconscious structures of the human psyche in the formation of ideological constructs. The author turns to the consideration of the concept of hjhj “illusory consciousne”of K. Marx and S. Freud’s theory of the unconscious and concludes that there is a certain similarity between them. The individual within the framework of both theories is not aware of the real reasons of his views, however in one case the source of his errors is the economic struggle, in the other – the struggle of internal drives. The author identifies two interrelated aspects of relationship between unconscious structures and ideology: genetic and functional. The genetic aspect allows us to observe how unconscious perceptions influence the formation of rationalized structures of ideology. The functional aspect shows how ideological constructs assert themselves in social practice, by appealing to people's unconscious intentions. The author considers that the ideology must also include a realistic, rational component, since it seeks to achieve real social and political goals, and not their fantasy embodiment.