Although the impact of education policy reform could inform future policymaking initiatives, studies on education policy reform of student assessment are considered scarce. This study attempts to scrutinise the drivers, impacts, and challenges of education policy reform of the national assessment system in Malaysia based on policy documents and previous empirical studies. The findings indicated that the education policy reform of the Malaysian national assessment system is driven by the decline of pupils’ performance in international large-scale assessments. There are changes in content, format, and structure of the public examinations and assessment delivery procedures. The emergence of school-based assessment shows a paradigm shift from cognitive learning to a more holistic manner. Challenges arise included teachers’ extra workload, teachers’ readiness, lack of reference materials, and time constraints in implementing school-based assessment. Findings inferred the needs in refining the monitoring and coaching system in order to ensure the student assessment implementation does not diverge from the missions of education policy reform. This study is hoped to provide useful insights for future policymaking initiatives, particularly in Malaysia. Keywords: Malaysia, policy reform, public examination, school-based assessment, student assessment. Cite as: Chin, H., Thien, L. M., & Chew, C. M. (2019). The reforms of national assessments in Malaysian education system. Journal of Nusantara Studies, 4(1), 93-111. http://dx.doi.org/10.24200/jonus.vol4iss1pp93-111