The aim of this paper is to examine the differences in particular dimensions of selfconcept in female and male adolescents depending on sports engagement, as well as to determine which domain-specific self-perceptions provide the highest contributions to global self-worth in female and male adolescents engaged in sport and those not engaged in it. This research included 400 subjects at early adolescent age, of both genders (235 females and 164 males) further divided to sub-samples of athletes and non-athletes. An adapted version of a scale Self-Perception Profile for Adolescents (Harter, 1988) was applied, which consists of nine subscales. The obtained results indicate that sport-engaged adolescents of both genders provide more favourable perception of themselves in most tested aspects of self-concept than those not engaged in an organized sports activity. Engagement in sport has special effect on selfconcept of male adolescents. Results of multiple regression analysis point out unambiguously the significance of self-perception of physical appearance in global self-worth of adolescents of both genders, irrespective of whether they are involved in sports activity or not.