In this systematic review, we evaluated the quality and rigor of the current evidence base for the Second Step social-emotional learning program in middle schools. Eleven studies were coded using the "Council for Exceptional Children Standards for Evidence-Based Practices in Special Education" with an 80% weighted criterion. We determined five studies met the weighted 80% criteria and one study demonstrated a positive effect as defined by Council for Exceptional Children. The other four studies demonstrated "neutral/mixed" results, and we therefore classified "Second Step" for middle schools in the mixed evidence category. We discuss the strengths of evaluated studies and future directions for research.