Benzodiazepines have been available for more than 30 years. At the time of their introduction, these drugs were heralded as a safe alternative to the widely prescribed and addictive barbiturates, and were greeted warmly by the medical profession and by patients. However, the addictive potential of benzodiazepines has been increasingly recognised, placing growing pressure on prescribers and patients to limit their use, especially in the long term.These precautions seem to have been effective, in that prescribing has decreased and the eruption of problems arising from addiction among patients on prescribed drugs appears to have passed its peak. On the other hand, benzodiazepines have been taken up by street drug abusers, not only at conventional doses and by the oral route, but also in larger doses and intravenously.Alarming new reports from several continents indicate a serious abuse problem, with major attendant risks in terms of mortality and morbidity in the future. Our understanding of the effects of large doses of benzodiazepines administered by the intravenous or oral route is extremely limited, and further clinical research into the physical, psychological and sociological implications of benzodiazepine abuse needs to be undertaken.