The UN Convention 1971 on Psychotic substances requires the World Health Organization to recommend psychotropic substances for international control. 2. This convention is based on evaluating the benefit and risk ratio, in particular on the public health and social problems associated with its use. 3. The UN Commission on Narcotic Drugs takes a final decision on these recommendations and is then binding in countries which are party to the convention. 4. Presently 34 commercially available benzodiazepines are under international control at minimum level, schedule IV of the 1971 convention, to be available on the physicians' prescription and not over the counter.