The evaluation found that most parents and youth recalled exposure to campaign antidrug messages. There was evidence of favorable campaign effects on four of five parent beliefs and behaviors known to influence youth's drug use, notably talking with their children about drugs, doing fun activities with children, and beliefs about monitoring their children's behavior and associations. There was little evidence of direct favorable campaign effects on youth, either for marijuana or early intervention initiatives, or for the campaign as a whole. Through most of the campaign period, there were significant delayed effects of campaign exposure on social norms and perceptions of other kids' use of marijuana, and these effects were consistently in an unfavorable direction, i.e., higher exposure leading to weaker anti-drug norms. The major campaign components were television, radio, and other advertising, complemented by public relations efforts that included community outreach and institutional partnerships. The evaluation consisted of nine data-collection waves of the National Survey of Parents and Youth, an in-home survey designed to represent youth living in homes in the United States, as well as their parents. Each of the first three waves enrolled a nationally representative sample of youth ages 9 to 18 and their parents. The respondents at these waves represented the approximately 40 million youth and their parents who were the target audience for the campaign. 16 tables and 4 references