Education policy research has seen a growing interest in the consequences of teacher trade unionism of global education reform. Less attention has been paid to teacher unions as strategic social actors attempting to influence both national education policy and employment relations at the school level. Addressing this topic, the article examines the challenges and dilemmas of teacher trade unions as they negotiate education policies in crisis contexts. With a particular concern for school and teacher evaluation, it focuses on reforms in Greek education, as these have played out in a period of structural adjustment and prolonged austerity (2010-2023). Drawing on interview data with leading members of the primary and secondary teacher unions, the article discusses the conditions in which reforms have emerged and the responses they have evoked from teacher unions in an education state undergoing historically significant change. It argues that the crisis provoked uncertainties of strategy in Greek teacher unionism. Nevertheless, unions maintain their identity as active components of movements for educational change and as organisations that aim to defend the status and working conditions of their members. Debates in Greece highlight a combination of economic and political aspirations, characteristic of teacher unions across Southern Europe.