Of the many Old World plants or plant products which have potential for abuse, kat has probably been the least publicized in so-called more economically developed countries. Because kat has rather localized used and because, unlike opium and hashish it has no documented history or well-developed tradition dating from remote antiquity, few outside the confined areas of use even know about it. While kat has been, and still is, used in traditional medicine, it cannot boast of any great potential for development as a drug for use in Western societies. In short, the incentives for detailed, serious investigation until recently have been lacking. Even so, there is a considerable, albeit scattered, body of literature which might help provide renewed insights in approaching what is seen by some as an increasingly serious kat problem. A multidisciplinary historical overview of the use, abuse and sociology of this important plant is presented. Special emphasis is given to European early knowledge of, and evolution of attitudes towards kat use. Alleged past use and development of contemporary use patterns, effects, legal aspects, and chemical composition is covered from an historical perspective as well.