In the perspective of the social sciences, social skills have been defined as behaviors that affect interpersonal relations. In our work, we refer to this interactionistic framework by conceiving social competence as the ability to use social interactions to satisfy one’s own goals and needs while at the same time considering the needs and goals of others. We differentiate between two dimensions: (a) self-oriented social skills which are aimed at satisfying one’s own needs (i.e. assertiveness and social participation) and (b) other-oriented social skills which are aimed at satisfying another’s goals and needs (i.e.. pro-social, cooperative behavior). We assume that these dimensions operate through different mechanisms on children’s and adolescents’ psychosocial adjustment. Our own studies on children, adolescents and young adults have shown that deficits in self-oriented social skills are strongly associated with low emotional well-being and depressive symptoms, whereas deficits in other-oriented social skills are associated with negative peer relations and conflicts with friends. To assess these two dimensions, we developed a 20-item questionnaire which can be completed by children, parents, and teachers (SOCOMP-questionnaire). In the current presentation, we will present data from different studies and age groups on the reliability, validity, stability and cross-informant agreement of the SOCOMP-questionnaire.