Submitted case study describes beginning, development and maintaining of the child s addiction as a product of dysfunctional family environment. Serious and unresolved conflict between parents creates an atmosphere of insecurity and leads to non-keeping the boundaries and consistent raising principles. Case study comes from the concept of family systems theory. System approach defines family as a system characterized by non-sumativity, interaction, homeostasis, dynamics and development. According to the family systems theory the symptoms of a child are related not only to its individual processes but also to the interpersonal processes within the family.

Key words: family – system approach – substance use