This study investigated how socio-economic factors influence academic achievement in the Kenya Certificate of Secondary Education (KCSE) within public day secondary schools in Runyenjes Constituency, Embu County, Kenya. The objectives that guided the research where to determine social factors affecting students’ performance, investigate economic factors affecting student performance, assess the cultural factors affecting student performance and to establish measures that can be put in place to improve students’ performance in Kenya certificate of secondary education. The research utilized a descriptive survey design involving 318 participants, including students, teachers, deputy principals, and principals. Findings revealed that students from higher socio-economic backgrounds tended to perform better in KCSE compared to those from lower socio-economic backgrounds. Factors such as parental income, educational background, and cultural practices were identified as significant determinants affecting students' academic success. Recommendations from the study emphasized the importance of enhancing parental involvement in students' education and implementing targeted interventions to provide equitable access to educational resources across all socio-economic levels.