The present study reports the evaluation results of the "Protecting You/Protecting Me" (PY/PM) alcohol use prevention and safety curriculum for third, fourth, and fifth graders when taught by high school peer leaders. The primary goal of the PY/PM prevention program, developed by Mothers Against Drunk Driving (MADD), is to prevent injury and death of children due to underage consumption of alcoholic beverages and vehicle-related risks, especially as passengers in vehicles in which the driver is not alcohol-free. Two classrooms for each grade were randomly assigned to receive either the Intervention or serve as a Comparison in four sites in Texas. From pre-test to post-test, 259 surveys were matched (Intervention n = 128, Comparison n = 131). A 6-week follow-up survey was also completed with 120 Intervention students. The results showed the Intervention group made significant improvements, relative to the Comparison group, in Vehicle Safety Skills, Intentions not to Ride with an Alcohol Impaired Driver, Media Literacy, and Knowledge about Brain Development. Additional findings showed some individual differences by gender and grade and that the intervention's effect varied in a few areas depending on pre-test score, gender, and grade. Overall, the curriculum benefits students by influencing their attitudes toward advertisements, increasing their intentions not to ride with a driver who has been drinking, developing their skills to protect themselves when they have no other option but to ride with an alcohol impaired driver, and improving their knowledge about the developing brain.