Walking is the most common type of physical activity (PA) and the likely target of efforts to increase PA. No studies, however, have identified the belief-level correlates for walking using the theory of planned behavior. This study elicits salient beliefs about walking and evaluates beliefs that may be most important for walking-promotion campaigns. A random sample of 55 Canadian adults participated in the elicitation study, and the validation study includes 358 participants who completed measures of demographics, beliefs from the elicitation study, and self-reported walking behavior. Belief--behavior relationships show that almost all behavioral expectancies are correlates of intention and behavior, but normative and control expectancies are more select correlates. But when belief--behavior relations are evaluated by participants meeting PA recommendations, only beliefs about feeling good, appearance, stress relief, and time are significant. Public health efforts to promote walking should focus on making time for regular walking and the affective advantages that walking can provide. (Contains 4 tables.)