This study integrated research on aggression, peer status, and social and academic functioning across the middle- and high-school transitions. We examined how peer status and aggression are related to adolescents' expectations about their academic and social functioning in a new school system before the transition into that system, and their perceived academic and social functioning after the transition. Social preference, perceived popularity, overt and relational aggression, and social and academic expectations were assessed in Grades 5 and 8; identical peer status and aggression constructs and perceived social and academic functioning were assessed in Grades 6 and 9. Results indicated moderate correlations between adolescents' social and academic expectations and perceived functioning across both school transitions. Girls reported higher social and academic functioning than boys did in most cases. Perceived popularity was consistently positively associated with academic and social expectations for middle and high school, whereas social preference was associated with perceived social functioning in both middle school and high school. The link between aggression and outcome variables varied by age and was moderated by gender and peer status.