Drawing from the contributions of vocational psychology, this study examined school engagement as a mediator of academic performance through the effects of career preparation (career planning, career decision-making self-efficacy), parental career support, and teacher support among diverse urban youth in middle school and high school (N = 285). Based on structural equation modeling, all structural paths of the proposed hypothetical model were significant. The effects of teacher support and parental career support on school engagement were mediated by career preparation; in turn, the effect of career preparation on grades was mediated by school engagement. Teacher support also had a direct effect on school engagement.The middle school students had significantly higher grades than the high school students, but there were no significant grade-level differences in terms of school engagement, career preparation, parental career support, or teacher support.The limitations of the study and its implications for research, practice, and public policy are discussed. (Contains 4 tables, 1 figure and 1 note.)