The STEM (Science, Technology, Engineering and Mathematics) Integration Initiatives of the Caribbean Examinations Council (CXC) have significantly impacted on education in the Caribbean landscape. CXC, as the premier assessment and certification provider in the Caribbean, prides itself on executing its mission to provide the region with syllabuses of the highest quality, valid and reliable examinations, and certificates of international repute for students of all ages, abilities, and interests. Firstly, this article will examine the CXC’s role as a provider of syllabuses as the blueprint for its certification products. Secondly, it will showcase the extent to which the School-Based Assessment (SBA), as the formative assessment component of the overall assessment package, supports the seamless incorporation of STEM principles. Finally, this article will provide exemplars of how CXC’s multi-faceted response to STEM has served as a catalyst for the transformation of teaching, learning, and assessment practices in the region.