In this study, two longitudinal models of early adolescent risky sexual behaviors (RSB) were compared using a pooled sample of 267 Canadian and Italian adolescents (55% females; 53% Canadians) assessed yearly from grade 8 to 10. We focused on parenting practices (monitoring, control, limit setting), adolescent problem behaviors (antisocial behaviors, substance use) and their friends' deviance (antisocial behaviors, substance use) as predictors of condom use frequency and lifetime number of sexual partners. The socialization model postulates that youths' problem behaviors and RSB are behaviors learned within the friendship network where deviancy training can occur. The selection model posits that delinquent youth tend to affiliate with each other, and that RSB is one of many behaviors that can form the basis of selection. Using structural equation modeling, this study showed that the socialization model was the most accurate to explain the emergence of RSB. A full mediation of parenting practices, passing through deviant friends and youths' problem behavior, was observed for condom use. The same process applied to number of sexual partners, but a direct effect for parenting practices was also found. (Contains 3 figures and 4 tables.)