The endocannabinoid system embraces a group of lipid molecules, enzymes and receptor proteins. This system appears to be involved in the modulation of neurotransmitter release thereby modifying learning and memory, in the regulation of food intake, and in the modulation of inflammation and pain and several other physiological/pathophysiological conditions. Furthermore, naturally occurring structural analogues of one of the endocannabinoids also appear to have beneficial biological activity in animal models of pain and obesity, although these endogenous compounds cannot activate cannabinoid receptors. The intention of this short review is to give an updated overview of this very large field from a biochemical and pharmacological point of view.