Obesity is increasing worldwide and has become a major health burden in Western societies affecting every third American and every fifth European. Obesity makes a major contribution to morbidity and mortality, predisposing individuals to cardiovascular disease and diabetes. Many new substances are currently being investigated for their usefulness in the pharmacotherapy of obesity. Most anti-obesity drugs can be divided into four groups: those that reduce food intake; those that alter metabolism; those that increase thermogenesis; and those that regulate hormone involved in feeding behavior. In this article we review these and other agents available in various countries for the treatment of obesity. Perhaps more importantly, we have focussed on areas of potential productivity in the future. Over the last 5 or so years, this impetus in obesity research has provided us with exciting new drugs targets involved in the regulation of feeding behavior and cellular mechanism involved in energy expenditure. Recent development in the quest for control of human obesity include the discovery of hormones, neuropeptides, receptors and transcription factors involved in feeding behavior, metabolic rate and adipocyte development. For developing new, perhaps even more specific pharmacological agents, further research is needed to understand the individual different genetic and physiological basis of obesity. It remains the hope of research scientists that in the not too distant future we shall see a new class of anti-obesity drugs arising logically from the molecular biology revolutions.