Risk beliefs are central to most theories of health behavior, yet many unanswered questions remain about an increasingly studied risk construct, anticipated regret. The authors sought to better understand anticipated regret's role in motivating health behaviors. The authors systematically searched electronic databases for studies of anticipated regret and behavioral intentions or health behavior. They used random effects meta-analysis to synthesize effect sizes from 81 studies ( = 45,618). Anticipated regret was associated with both intentions (+ = .50, < .001) and health behavior (+ = .29, < .001). Greater anticipated regret from engaging in a behavior (i.e., action regret) predicted weaker intentions and behavior, whereas greater anticipated regret from not engaging in a behavior (i.e., inaction regret) predicted stronger intentions and behavior. Anticipated action regret had smaller associations with behavioral intentions related to less severe and more distal hazards, but these moderation findings were not present for inaction regret. Anticipated regret generally was a stronger predictor of intentions and behavior than other anticipated negative emotions and risk appraisals. Anticipated inaction regret has a stronger and more stable association with health behavior than previously thought. The field should give greater attention to understanding how anticipated regret differs from similar constructs, its role in health behavior theory, and its potential use in health behavior interventions. (PsycINFO Database Record