This short-term longitudinal research examined the relationships among middle school students' perceptions of school environment, school engagement, and academic achievement. Participants were from a representative, ethnically diverse, urban sample of 1,046 students. The findings supported the theoretical conceptualization of three different, but related, dimensions of school engagement: school participation, sense of identification with school, and use of self-regulation strategies. The results also indicated that students' perceptions of the distinct dimensions of school environment in seventh grade contribute differentially to the three types of school engagement in eighth grade. Finally, the authors found that students' perceptions of school environment influenced their academic achievement directly and indirectly through the three types of school engagement. Specifically, students' perceptions of school characteristics in seventh grade influenced their school participation, identification with school, and use of self-regulation strategies in eighth grade that occur therein and, in turn, influenced students' academic achievement in eighth grade. (Contains 4 tables, 2 figures, and 1 note.)