For several years, a Philadelphia vacant lot greening program has worked to repurpose empty lots in disadvantaged neighborhoods. PISC Advisors John MacDonald, PhD, and Charles C. Branas, PhD, examined the influence of this program on crime rates within the neighborhoods. Crime rates were evaluated using difference-in-difference models to assess the impact of the vacant lots on the surrounding area. Overall, neighborhood crime rates dropped significantly when empty lots were repurposed. Vacant lot greening was most successful when the repurposed lots were not near train stations or alcohol stores. In conclusion, vacant lot greening has proved to be both a successful and sustainable method in crime reduction.