This study reports results from a large population-based survey of U.S. adults showing perceived behavioral control (PBC) moderations of associations between (a) attitude and intention and (b) perceived norms and intention to engage in 6 health behaviors. Results are based on data collected from a nationally representative sample of U.S. adults ages 40-70 (N = 2,489) and extend understanding of how behavioral theory can be used to guide the design and evaluation of health communication campaigns. Ordinary least squares regression analyses show evidence of a significant positive PBC moderation of (a) attitude and intention and (b) perceived norms and intention such that attitude or perceived norms toward the behavior is more strongly associated with behavioral intention among participants reporting higher levels of PBC. Implications for message design and the evaluation of communication campaigns are discussed.