The Marijuana Education Initiative’s Impact Awareness curriculum is designed to promote youths’ informed decision making about marijuana use. This curriculum presents evidence-based information about health and behavior risks associated with youth marijuana use and abuse, differences in medicinal and recreational use, and communication skill building. The school-based curriculum is intended for implementation in a health or science class during five 50-minute sessions. The evaluation included in this meta-analysis was for a curriculum targeting high school students. Students attending comparison group high schools received their schools’ standard curriculum.