Introduction. Pedagogy at the turn of the 19th century was preoccupied with the problem of how to care for neglected, and even delinquent, children. Many groups, including psychologists, doctors, sociologists, and lawyers, have voiced their opinions about how these children should be resocialised. One of the lawyers dealing with the topic was Aleksander Mogilnicki (1875-1956), who gave numerous presentations about possible care strategies for young delinquents. He also co-founded the International Organization for the Protection of Children (Association international pour la protection de l’enfance). Aim. This publication shows Mogilnicki’s approach to childcare. Materials and methods. The main texts analysed are his works: Dziecko i przestępstwo [Child and Crime] (1916), and Dziecko wobec prawa [Child and the Law] (1921), in which he showcased the contemporary legal situation and resocialization possibilities. Results. Aleksander Mogilnicki is one of the pioneers of rehabilitation pedagogy. He pointed out the role of the family in upbringing, as well as legal solutions and the tasks of educators with regard to criminal children.