The paper deals with morally defective youth as part of the social history of interwar Czechoslovakia. The research is based on the text of the professional periodical Úchylná mládež from 1925 to 1934. This is a topic not yet elaborated in detail in Slovak historiography, which was the main motive for the research. The aim of the study is to characterize morally defective youth in more detail, to describe their manifestations, to find out the causes of its origin and to describe how and where they were re-educated. The work also reveals specific cases approaching the family and social environment of morally defective youth.