Background: Turn 2 Us (T2U) is an elementary school-based mental health promotion and prevention program in New York City. It targets fourth- and fifth-grade students at risk for social/emotional and behavioral problems and provides a range of services to students, staff, and parents. The purpose of this study is to determine if T2U decreases internalizing and externalizing behaviors in participating students. Methods: Teachers measured students' symptoms before and after participation using the strengths and difficulties questionnaire (SDQ). Change in the total SDQ score was analyzed using Wilcoxon rank-sum nonparametric testing. We assessed the effects of covariates on the score change with linear regression models. Results: The 185 unique students who participated in the intervention showed a significant improvement in total SDQ score (Z = -4.107, p < 0.001). Students who were at higher risk prior to the intervention showed greatest improvement in behaviors. None of the covariates assessed affected the change in SDQ score. Regression models showed that higher initial SDQ scores predicted higher post-intervention SDQ scores ([beta] = 0.681, p < 0.001). Conclusion: T2U significantly decreased internalizing and externalizing behaviors in participating students, with the greatest impact for highest risk students. This study helps validate T2U's unique and comprehensive approach.