The present research examined the relationship between self-concept and level of involvement in delinquent activities of 1327 (612 males, 715 females) years 8-12 high school students. Through cluster analysis, participants were identified as having either high or low involvement in delinquent activities from scores on a self-report measure of delinquency. Three multidimensional areas of self-concept (classroom, peer and confidence) were investigated, because of previous findings indicating discrepancies in these three dimensions for adolescent involvement in delinquent activities. Four, two-way multi-variate analyses of variance were conducted across the three self-concept dimensions for Gender, Year Level, and involvement in Delinquent Activities. Students highly involved in delinquent activities reported significantly lower classroom, peer and confidence self-concepts. For gender and year level effects, males reported significantly higher confidence self-concept while females scored significantly higher on peer self-concept. There were significant differences among year levels with a general decline in confidence self-concept with age but for classroom and peer self-concept, no clear age trends were evident. The results indicate the importance of considering multidimensional self-concept when examining adolescents' involvement in delinquent activities and incorporating self-concept enhancement strategies in intervention programs. (Contains 7 tables.)