The aim of this study was to explore the role of theory of mind - the ability to attribute mental states to other people to explain their behavior - in the development of social competence and prosocial behavior in adolescence. It is assumed that there is a difference in the manifestation of prosocial behavior and social competence in adolescents with different levels of theory of mind. Participants were 95 adolescents aged 12–15 years (M=13.8; SD=9.5; 46 girls). We used “Reading the Mind in the Eyes” test to assess the social-perceptual component of theory of mind (assessment of the recognition of mental states by facial expressions) and the task of understanding higher-order false beliefs to assess the socio-cognitive component. We assessed the adolescent’s prosocial behavior during a group game of puzzles and calculated the ratio of the number of prosocial acts to time in seconds. Teachers assessed the social behavior of adolescents using a specially designed questionnaire. We also used a sociometric method to study the popularity of adolescents in the group. The results obtained testify to the different contribution of the socio-perceptual and socio-cognitive components of theory of mind to the development of social competence of adolescents. Adolescents who better understand the mental states of others and predict their behavior are more likely to act prosocially, are more persuasive and successful in mastering the school curriculum. Teachers are rated those who better recognize mental states by facial expressions as more helpful and popular among their peers. Adolescents with low level of theory of mind are rejected by their peers.