Alcohol use among adolescents has been declining for years, yet evidence of the effectiveness of alcohol control policies intended to limit underage drinking is mixed. This brief examines the relationship between 14 state underage drinking laws and drinking prevalence among U.S. high school students, using data from four years (between 2005 to 2011) from the Youth Risk Behavior Surveillance Survey (YRBSS), the Alcohol Policy Information System (APIS), and Child Trends’ own state policy database.