The purpose of this study was to investigate the factors affecting the academic performance of students in mathematics in the selected schools of Embu District in Kenya. The specific objectives of the study were to investigate some factors responsible for the students' academic performance in Mathematics. The methods used for data collection were questionnaires and interview guides to gather information on the academic performance in mathematics. The findings revealed that discipline, Quality of teachers and school facilities affect academic performance in mathematics in the selected schools of Embu District. The study recommended the government to have a palicy in place that encourages retaining teachers in upcountry schools; where government should consider introducing upcountry allowance in the remuneration scheme of mathematics teachers among other recommendations.