Test-based accountability (TBA) draws on a managerialist ideology that emphasises standards, constant measurement, and external motivation for improvement. It stands in sharp contrast to the idea of professional learning communities (PLCs) that aim to mobilise teachers' internal motivation and willingness to cooperate with peers to facilitate a joint, self-reflective inquiry process of pedagogical improvement. The Israeli education system has adopted TBA policies. To determine how this affects a professional learning programme focused on reflective inquiry, we analysed staff discussions recorded in 180 PLC meetings in 17 schools. The study suggests that TBA not only narrows the curriculum and the repertoire of pedagogical practices used by teachers but also constrains the ability of teacher professional learning to counterbalance these negative consequences.