The paper examines the process of establishing a teacher evaluation system in Chile and its acceptance by teachers over time. The conceptual base upon which the system was established is described. Evidence is also examined from a variety of data sources and research related to the evaluation system as well as teachers' use of its results. This evidence includes information from an external review of the system noting tensions between the formative versus accountability purposes of the evaluation system and that are being attended to in the new Teacher Professional Development Law (2016).