In Flanders (Belgium), a new teacher evaluation policy was issued which placed a lot of autonomy with school principals to develop and implement a new teacher evaluation system. In this study, we explore how Flemish principals perceive the new teacher evaluation policy and what influences their perception. Results demonstrate that principals perceive the policy as clear, but they are rather negative about the need, practicality, and complexity of the summative teacher evaluation. This perception is influenced by policy, context, and individual factors as is demonstrated in our qualitative analyses.