School-based sex education programmes have been implemented in South Africa to address adolescent sexual behaviors and reproductive health outcomes. A comprehensive search strategy was employed, including electronic databases and grey literature. Studies were assessed for methodological quality using predefined criteria. Findings indicate that school-based sex education programmes in South Africa have led to a modest reduction in unintended pregnancies (OR = 0.87, CI: 0.79-0.96). Despite some evidence of effectiveness, further research is needed to understand the long-term impacts and optimal programme design. Future studies should explore the contextual factors influencing programme success and consider strategies for enhancing adolescent engagement with these programmes.