Knowledge of the cannabinoid system and its components has expanded greatly over the past decade. There is increasing evidence for its role in the regulation of food intake and appetite. Cannabinoid system activity in the hypothalamus is thought to contribute to the homeostatic regulation of energy balance, under the control of the hormone leptin. A second component of cannabinoid-mediated food intake appears to involve reward pathways and the hedonic aspect of eating. With the cannabinoid system contributing to both regulatory pathways, it presents an attractive therapeutic target for the treatment of both obesity and eating disorders.