School psychologists have the potential to contribute to the development and delivery of health and mental health services through school-based health centers (SBHCs). Possible roles for school psychologists within SBHCs are described. Factors that influence school psychologists' efforts within SBHCs are discussed, including factors such as system reforms, school system governance, importance of SBHC to stakeholders, and availability of funding. Knowledge of collaborative problem solving, effective prevention and intervention strategies, and recognition of limitations of traditional mental health programs were also identified as facilitators of the school psychologist's role in a SBHC. Factors that may impede the development of SBHCs are reviewed. These factors include definitional confusion, deemphasis on prevention, community stigma, limited resources, lack of integration and coordination of services, and an emphasis on a narrow role of providing only medical services. Additional factors discussed include the narrow role of school psychologists, space limitations, the challenge of collaboration, role strain, and lack of research on interventions within a SBHC. Strategies for overcoming barriers are suggested.