This paper addresses the perceived consequences of the Chilean national teacher evaluation system. We interviewed 57 school leaders in 30 schools across 10 municipalities about effects and uses of the assessment in their schools. Results show that in the large majority of schools our interviewees observe positive effects such as increased teamwork and internal reflection processes based on the assessment results. Reports about effects at teacher level far outnumber institutional effects, and are mixed. In all schools our interviewees report on teachers' negative emotions and work overload due to the assessment process, but also about their internalization of the underlying professional standards. The paper analyzes differences among schools and offers suggestions for the development of large-scale standardized teacher evaluation systems. (Contains 2 tables.)