Summary Cholecystokinin (CCK), a peptide that is distributed widely throughout the gastrointestinal tract and the central nervous system, has a number of physiological effects including the stimulation of gallbladder contraction and pancreatic and gastric acid secretion, slowing of gastric emptying and suppression of energy intake. This review focuses on current knowledge relating to (i) the effects of CCK on energy intake; (ii) the role for CCK in the pathophysiology of obesity; and (iii) the therapeutic potential for strategies which modulate the action or secretion of CCK in the management of obesity. While CCK plays a role in the acute regulation of appetite and energy intake, there is little evidence to suggest that specific CCK receptor agonists, or modulation of the actions of endogenous CCK by dietary manipulation, have sustainable inhibitory effects on energy intake. Hence, it appears unlikely that manipulating the pathways by which CCK modulates energy intake will prove to be an effective strategy in the long term management of obesity.