This study aimed at identifying and describing patterns of sports participation during high school among a general population of students and examining individual, social, and environmental predictors of pattern membership. A sample of 287 high school students (61% girls) from Quebec (Canada) annually reported all the organized sports in which they had participated over the school year during five consecutive years (from Grade 7 to 11; in the Quebec school system, high school is comprised of five years). The predictors were assessed at the end of elementary school (Grade 6). Latent class analyses brought out four different patterns (specialized, moderate-sports, low-sports and no-sport participation). Multinomial logistic regressions revealed that adolescents' sex, parental involvement, best friends' participation in sports and family income were significant predictors of pattern membership. Parental involvement and family income significantly predicted membership in the specialized pattern relative to other patterns, suggesting that tangible support from parent is necessary for youth to maintain their long term commitment in a single sport. Findings highlight that efforts aimed at promoting sport participation during adolescence should target girls and encourage parents to get involved in their children's organized sports.