Two focal social cognitive processes were evaluated in a structural model for their direct and indirect roles in early adolescents' jealousy surrounding their closest friend in a sample of 325 early adolescents (169 girls and 156 boys) ages 11-14 years. Individuals who are rigid and unrealistic about meeting their friendship needs were more vulnerable to feelings of jealousy than individuals who think more flexibly. Inflexible individuals also engage in more jealousy-driven surveillance and other problem behavior towards their friends. Stronger jealous feelings and behavior were related, in turn, to greater conflict with friends and to a vulnerability to emotional maladjustment. In addition, young adolescents who tended to ruminate over friendship problems were also more vulnerable to jealousy. Inflexible attitudes and friendship rumination were positively associated. Results extend recent models of friendship jealousy that focus only on early adolescents' self-worth.