Unaddressed behavioral and socioemotional difficulties impact the mental health, educational attainment, and future outcomes of children to such an extent that it is imperative to identify effective strategies for early intervention and treatment. School-based mental health services address students’ socialemotional concerns by removing barriers to accessing appropriate services, improving coordination of services, and implementing prevention and intervention strategies for students. This study evaluates the effects of one such program on the socioemotional well-being of students served across six elementary school sites. Study findings support the critical need for school-based mental health for the promotion of prosocial behavior and socioemotional wellness.