The campaign is designed to address youth directly as well as indirectly, which included encouraging parents and other adults to take actions known to prevent youth drug use. The major intervention components include television, radio, and other advertising, complemented by public relations efforts that focus on community outreach and institutional partnerships. The campaign has progressed through three phases of increasing complexity and intensity. Phase III, upon which this report focuses, began in September 1999 and is scheduled to run at least through spring 2003. The primary tool for this evaluation was the National Survey of Parents and Youth, which is collecting initial and follow-up data from nationally representative samples of youth between 9 and 18 years old, as well as parents of these youth. This evaluation encompasses the first five waves of the survey (September 1999 through June 2002). The survey found that most parents and youth recalled exposure to campaign antidrug messages. Approximately 70 percent of both groups reported exposure to one or more messages through all media every week. There continues to be evidence consistent with a favorable campaign effect on parents. Overall, there were favorable changes in three out of five parent belief and behavior outcome measures, including talking about drugs with and monitoring of children and youth. Also, parents who reported more exposure to campaign messages scored better on four out of five outcomes after applying statistical controls to adjust for the possible influence of other explanatory factors. There was little evidence of direct favorable campaign effects on youth. There was no statistically significant decline in marijuana use to date, and there was some evidence of an increase in use from 2000 to 2001. Neither were there improvements in beliefs and attitudes about marijuana use between 2000 and the first half of 2002. There continues to be evidence of an unfavorable delayed effect of campaign exposure from the period September 1999 through June 2001 regarding subsequent intentions to use marijuana; other beliefs that could promote drug use were involved as well. Although intentions are strong predictors of subsequent initiation of marijuana use, the evidence for an unfavorable effect on actual initiation was not statistically significant overall or for any subgroup. 79 tables, 26 figures, 17 references, and appended detailed information on sample design, weighting, and variance estimation, data collection procedures, methods used to control for the effects of confounding variables, the ads in the campaign, and the preparation of the exposure indexes and the outcome indexes