Hierarchical regression analyses conducted at the school level found that the perceived prevalence of teasing and bullying was predictive of schoolwide passing rates on state-mandated achievement testing used to meet No Child Left Behind requirements. These findings could not be attributed to the proportion of minority students in the school, student poverty, school size, or personal victimization, which were statistically controlled for. Measures of the prevalence of teasing and bullying were obtained from a statewide survey of 7,304 ninth-grade students and 2,918 teachers aggregated into school-level scores for 284 Virginia high schools. These results support the need for greater attention to the effect of teasing and bullying on high school student performance on high-stakes testing.