The aim of this study was to examine the predictors of offender adolescents' problem and prosocial behaviors. Among the predictor variables individual characteristics (anger and impulsivity of adolescent), friends' behaviors (deviant and prosocial), and maternal monitoring and rejection were examined. It was also aimed to determine whether individual characteristics of adolescents have the mediational role in the relations between maternal characteristics and friends' problem and prosocial behaviours. Participants were 157 offender adolescents from penal institutions in Ankara. The results of hierarchical regression analyses revealed that problem behaviors of offender adolescents were positively predicted by maternal rejection and friends' problem behavior. The offender adolescents' prosocial behaviors were negatively predicted by maternal rejection and positively predicted by friends' prosocial behaviors. A series of regression analyses and Sobel test results revealed that individual characteristics of adolescent mediated three relations. Firstly, impulsivity had a mediational role between maternal rejection and friends' deviant behaviors. Secondly, anger control mediated the relationship of maternal monitoring with deviant friends, and lastly anger control had a mediator role between maternal monitoring and prosocial friends. The findings indicated that parents and friends have important contributions both on problem and prosocial behaviors of adolescents. And also temperamental characteristics of adolescent have partially explained the relations between parenting and friend selection of offender adolescents.