Perceptions of control hold a dominant position in social cognitive theories yet there is a lack of conceptual and empirical clarity regarding what kind of control is most associated with particular behaviours. Three prominent types of control are perceived control (PC), perceived difficulty (PD), and perceived confidence or self-efficacy (SE) for performing the desired behaviour. Three studies are presented with a primary goal of distinguishing PC, PD, and SE from each other, and a secondary goal of determining which of the three is the superior predictor of health-related intentions and behaviours. The first study replicates earlier work by Trafimow et al. (2002) distinguishing the three constructs for reading 1, 30, and 100 pages, and extends it to exercising one, two, four, and six times per week and also to predicting intentions to exercise 4 days per week and behaviour 1 week later. The second study examines the predictive capability of the three constructs for intentions to floss one's teeth everyday and to eat 5–10 servings of fruits and vegetables everyday and subsequently on behaviour assessed 7 days later. The third study reports a meta-analysis of the relative influence of PC, PD, and SE on behaviours when defined in conceptually consistent ways. The results of all three studies support the conceptual and empirical distinction of PC, PD, and SE and the superiority of SE as a predictor of health behaviours and intentions.