Among Latin American countries, Peru has one of the highest crime rates, with 9 out of 10 Peruvians reporting feeling unsafe walking the streets at night. This rooted-in-reality feeling of insecurity may harm citizens' mental health. We study the consequences of the Peruvian Safe Neighborhood program, which increased police patrolling in selected neighborhoods, on the mental health of residents. We exploit the program's staggered implementation and use data from the Demographic and Health Survey to precisely geolocate the respondents' residencies. Our results show that enhanced crime prevention reduced the incidence of mental health problems by 6 percentage points. In particular, the program reduced depression, tiredness, concentration problems, suicide intentions, and sense of failure by 3–4 percentage points. The evidence suggests that improvements in mental health are driven by tangible changes in health-related behaviors. Following the implementation of Safe Neighborhood, there is an increase in healthcare utilization.