The primary tool for the evaluation was the National Survey of Parents and Youth (NSPY), 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 report presents analyses from the first seven waves of NSPY. Also included in the report are statistics on the level of exposure to messages achieved by the Media Campaign during Phase III. For Phase III, advertising space was purchased on television, radio, newspapers, magazines, billboards, transit ads, bus shelters, movie theaters, video rentals, Internet sites, Channel One broadcasts in schools, and other appropriate venues. The focus was on the negative consequences of marijuana use. The NSPY found that most parents and youth recalled exposure to campaign anti-drug messages. Approximately 70 percent of parents and nearly 80 percent of youth reported exposure to one or more messages through all media channels every week. Recall of television advertising has increased across the 3.5 years of the campaign. Overall, there was evidence of some favorable campaign effects on four of five parental belief and behavior outcome measures, including talking with children about drugs, doing fun activities with children, and beliefs about monitoring children; however, the evidence for campaign effects on actual parents' monitoring behavior was much weaker. This is of some concern, because this is the parental behavior most associated with youth nonuse of marijuana. There was no evidence of favorable indirect effects on youth behavior or beliefs as the result of parental exposure to the campaign. Neither was there significant evidence of direct favorable campaign effects on youth, either for the marijuana initiative period or for the campaign as a whole. Youth who were more exposed to campaign messages were no more likely to hold favorable beliefs or intentions about marijuana than were youth less exposed to those messages, both during the marijuana initiative period and over the entire course of the campaign. 86 tables and 23 figures