This study examined the relations between the schoolwide prevalence of teasing and bullying (PTB) and schoolwide academic performance in a sample of 271 Virginia middle schools. In addition, the study examined the mediating effects of student engagement. A three-step sequence of path models investigated associations between schoolwide PTB and state-mandated Standards of Learning test pass rates, with effects examined both directly and indirectly through student engagement while controlling for important school-level characteristics. Separate models were examined for two 7th-grade and four 8th-grade tests. Results indicated that higher levels of both teacher and student perceptions of schoolwide teasing and bullying were significantly associated with lower achievement pass rates and student engagement. The relationship between perceptions of schoolwide teasing and bullying and achievement was partially mediated by student engagement. These findings bring new support for the need for schoolwide interventions to reduce teasing and bullying among middle school students.