This paper examines the effect of school mobility rates on the performance of different groups of students in North Carolina. We use detailed administrative data on North Carolina students and schools from 1996 to 2005 and follow four cohorts of 3rd graders for six years each. We find school mobility rates, were highest for minority and disadvantaged students, declined across successive cohorts for Hispanic students, but increased for Black students. Also, school mobility hurt the math performance of Black and Hispanic students, but not that of white students, and improved the reading performance of white and more advantaged students, but had no effect on the reading performance of minority students. Strategic school moves (cross-district) benefitted or had no effect on student performance, but "reactive" moves (within district) hurt all groups of students. White and Hispanic students were more likely to move to a higher quality school and Blacks students, to a lower quality school. Negative effects of school mobility increased with the number of school moves.