Mental health issues affect 20-25% of children and adolescents, of which few receive services. School-based health centers (SBHCs) provide access to mental health services to children and adolescents within their schools. A systematic review of literature was undertaken to review evidence on the effectiveness of delivery of mental health services in SBHCs. Databases were searched extensively for research studies published between January 1990 and March 2014. Data analysis was based on the method proposed by the Centre for Reviews and Dissemination. Twenty-three studies were selected for review. Each study was explored for accessibility and content of mental health services in SBHCs. SBHCs provide access and eliminate barriers to mental health services. Students who exhibited high-risk behaviors were more likely to have sought services at the SBHC. However, there is a lack of high-quality research evaluating mental health services in the SBHCs and their effect on children and adolescents.