Using a two-round longitudinal panel data set from the National Survey of Parents and Youth (NSPY), the present study examined the roles of antidrug-related community activities at both individual and aggregate levels in the National Youth Anti-Drug Media Campaign. This study found a main effect of parent’s antidrug-specific community activities on targeted parent-child communication about drugs. More interestingly, parents who did not actively participate in antidrug-related community activities were more likely to talk about drugs with their offspring after being exposed to the antidrug campaign ads than were their counterparts. In contrast, there was little evidence for a contextual effect of aggregate-level antidrug-specific community activities on targeted parent-child communication or for its cross-level interaction with campaign exposure. The implications of these findings for communication research and public health intervention efforts were discussed.