This paper describes an evaluation of Protecting You/Protecting Me (PY/PM), a classroom-based, alcohol-use prevention and vehicle safety program for elementary students in first through fifth grades developed by Mothers Against Drunk Driving. PY/PM lessons and activities focus on teaching children about (1) their brains (why their brain is important, how their brain continues to develop throughout childhood and adolescence, what alcohol does to the developing brain, and why it is important to protect their brain); (2) vehicle safety (what to do to protect themselves should they ever ride with an impaired driver); and (3) life skills (decision making, stress management, and media literacy). Fourth- and fifth-grade students from schools in the fourth year of PY/PM implementation were surveyed. Results indicated that, relative to comparison students from matched schools, PY/PM students increased their knowledge of alcohol's effect on development; gained decision-making, stress-management, and vehicle safety skills; and demonstrated changes in attitudes toward underage alcohol use and its harm. Further, students retained lessons learned in previous years and their scores improved with increased exposure to PY/PM. In addition, the findings demonstrate that it is possible to design and implement a program that can improve young children's knowledge regarding alcohol and their developing brains, teach them skills to protect themselves in dangerous situations, increase already high antialcohol attitudes, and change perceptions of alcohol's harmfulness.