The global popularity of test-based accountability appears to signal political trust in standardised assessments as valid and relevant measures of education quality. Nonetheless, research shows that educators’ perceptions of standardised testing and test-based accountability can vary significantly, as do their responses to accountability demands. Considering the key influence of teachers’ beliefs on the way in which they respond to education reforms, in this paper we examine teachers’ beliefs and opinions about standardised tests and test-based accountability. We rely on a comparative study on the interpretations and experiences of standardised testing and test-based accountability demands of compulsory education teachers in Chile and Norway. These cases were selected following a most-different-systems design approach. By relying on data derived from an electronic survey (n=2,531) and in-depth interviews (n=60), the analysis shows how in both contexts, teachers are relatively critical about the validity, usefulness and fairness of the standardised tests, signalling a lack of trust of teachers in standardized testing and test-based accountability. Still, despite similar trends, some key differences in the beliefs of Chilean and Norwegian teachers are found, which highlight the influence of the sociocultural context in shaping teachers’ beliefs. By illuminating how teachers in different contexts make sense of test-based accountability, our analysis contributes to the understanding of why the often-reported mismatch between policy expectations and policy outcomes might occur.