Caffeine is the most widely used psychoactive substance in the world. In Western society, at least 80 per cent of the adult population consumes caffeine in amounts large enough to have an effect on the brain. Is this due to caffeine dependence? The article reviews the abuse potential of caffeine in relation to its mechanisms of action. Caffeine affects the same parts of the brain as cocaine, but in completely different ways. There is evidence for caffeine withdrawal symptoms, and caffeine does act as a weak reinforcer, but neither effect is as pronounced as those associated with cocaine. Nor does caffeine use appear to pose any threat to the individual or to society. There is thus no need to add diagnosis "caffeine dependence" to the psychiatric manuals.