This systematic review examines the state of high school teachers' mathematical knowledge base for effective instruction in Ghana. The review encompasses studies conducted between 2014 and the present. The objective is to provide a comprehensive analysis of the current status, strengths, weaknesses, and factors influencing teachers' mathematical knowledge. The review also explores the implications of teachers' mathematical knowledge on instructional practices and student learning outcomes. The study reveals that while some teachers in Ghana possess a strong mathematical knowledge base, there are challenges in developing and maintaining this knowledge. Limited access to professional development opportunities, time constraints, and lack of resources are key obstacles. The review emphasizes the importance of pre-service teacher education programs, ongoing professional development, supportive networks, and curriculum design in enhancing teachers' mathematical knowledge. Recommendations include strengthening pre-service education, providing professional development opportunities, and creating supportive networks. The findings underscore the critical role of teachers' mathematical knowledge in effective mathematics instruction and call for further research and investment in teacher professional development to improve mathematics education in high schools. Keywords: mathematical knowledge, high school teachers, effective instruction, Ghana, systematic review, pre-service teacher education, professional development, curriculum design, knowledge sharin
