Education is a major catalyst in the development of the country. School Based Assessment (SBA) is a new transformation in Malaysian education that required subject teachers to conduct formative assessment during teaching and learning process according to the procedures by Malaysian Examination Syndicate (MES). Thus, teachers play an important role in the implementation of the national education policy in order to develop students' potential and achievement in physical, emotional, spiritual and intellectual. This requires teachers' contributions of effort, involvement, and overall professionalization. This study aims to investigate teachers' readiness, understanding, and workload in implementing SBA. Further, this study also seeks to determine the relationship between teachers' understanding and workload, as well as between teachers' readiness and workload. Participants were comprised of 260 teachers from primary schools in the district of Kerian. The results showed that the level of teachers' understanding and readiness towards implementing SBA is high. However, the workload level among teachers was also high. Correlation analysis indicated that there is a significant negative relationship between teachers' understanding and readiness with the level of workload. [For the complete proceedings, see ED557311.]