We examined the effectiveness of the "Say Something Anonymous Reporting System" (SS-ARS) program in improving school safety in a cluster randomized control trial among over 700 students in 19 middle schools in the Miami-Dade County Public Schools. The SS-ARS is a program that emphasizes youth engagement and trains youth to recognize warning signs of possible harmful behaviors and to safely report potential threats. We compared 3-month posttest reports of students' self-efficacy and intention to report warning signs and 9-month posttest perceptions of school and exposure to school violence in treatment versus control schools. Results show that SS-ARS improved both 3-month and 9-month self-efficacy and intention to report. The intervention also promotes perceptions of school safety and reduced violence exposure at 9-month posttest.