This study examined gender differences in adolescent participation in sport and physical activity, in teasing experiences specific to the physical activity domain, and the relationship between adolescent physical activity and body image. A sample of 714 adolescents (332 girls, 382 boys) aged between 12 and 16 years completed measures of participation in organised sport and other physical activities, experiences of teasing specific to sport, self-objectification and body image. Adolescent girls participated in organised sport at a lower rate than boys, but experienced higher levels of teasing. Both girls and boys reported being teased by same-sex peers, but in addition, girls also reported being teased by opposite-sex peers (i.e. boys). Time spent on aesthetic physical activities was related to disordered eating symptomatology for both girls and boys. It was concluded that teasing and body image concerns may contribute to adolescent girls' reduced rates of participation in sports and other physical activities. Copyright © 2010 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.