Proposals to use teachers’ performance incentives have recently attracted considerable attention. However, there is very little experience with applying incentives in schools. This paper provides evidence on the causal effects of two programs: the first provided the school and its teachers with monetary performance incentives and the second with additional conventional resources. The assignment of schools to the two programs was not random; therefore, identification is a central issue in the empirical analysis. The empirical results suggest that schools’ and teachers’ group monetary incentives caused significant gains in many dimensions of students’ outcomes. Endowing schools with more resources also led to improvement in student performance. However, the comparison based on cost equivalency suggests that the teachers’ incentive intervention is much more cost effective.