A new evaluation of a violence prevention program for middle schools finds that after one school year, there were no statistically significant impacts on how often students reported that they were victimized by their peers, or committed violence against their peers. In addition, there were no statistically significant impacts of the program on a number of other outcomes such as how often students' reported positive behavior toward their peers or on their perceptions of school safety. The report, Impacts of a Violence Prevention Program for Middle Schools: Findings From the First Year of Implementation, uses survey data collected from sixth-grade students in 40 middle schools, with half of the schools assigned by lottery to receive the violence prevention program. The findings held for both the full sample of students and a subgroup of students identified as high-risk for violent behaviors. The violence-prevention program consisted of both a curriculum (Responding in Peaceful and Positive Ways) and a whole-school component (Best Behavior). The purpose of the program is to provide middle schools with a comprehensive approach to violence prevention that targets both individual students and the school environment. A second report is expected and will include findings from two and three school years of implementation.