Educational change initiatives, whether they involve the implementation of new policies or curriculum reforms, often fail to reach the level of teachers' classroom practices. In the search for explanations, numerous studies have either characterized teachers as resistant to change or focused on how schools' workplace conditions have failed to influence teacher change. This study draws attention to these issues by investigating teachers' perceptions of the degree to which a national curriculum reform has brought about changes in their teaching. The study also proposes a model of how teachers' perceptions of school-based conditions (i.e., school leadership, teacher collaboration, and development of school-based curricula) are related to teachers' general orientations towards change and teachers' perceptions of change as a result of the reform. The participants were 738 Norwegian teachers in public primary and lower secondary schools, and the data were analyzed using descriptive data, correlation analysis and structural equation modeling (SEM).The results indicate that the overall influence of the reform on teachers' teaching was moderate. The results also revealed positive relationships between teachers' perceptions of school-based conditions, teachers' general orientations towards change and the degree of perceived reform changes in teachers' teaching. However, a surprising finding is that school leadership and teacher collaboration were only indirectly related to teachers' perceptions of reform changes, mediated through teachers' general orientations towards change. The article highlights important relationships between educational reform, school-based conditions and teachers. It also contributes knowledge that is relevant to consider for successful reform of schools and education.