In a longitudinal study of 1230 people aged 13-18 years from the Greater Oslo Area, the past-year prevalence of anxiolytic or hypnotic use was 10%, which is higher than previously reported. The majority gave therapeutic reasons as a motive for using these drugs. However, most of the use was unprescribed. The parents, and especially the mother, were the most important suppliers. A minority gave intoxication as a motive for using these drugs. In this group, the suppliers were mainly peers and the illegal market. Neither the unprescribed nor the prescribed therapeutic use show any association with use of drugs such as alcohol and cannabis. There is, however, a strong association between the unprescribed use of benzodiazepines by young people and by their parents. This suggests a pattern of learning and role modelling, which must be regarded as problematic for public health policy. Those who use the drugs to become intoxicated have particularly poor mental health, and they use many other drugs as well. This group probably runs a special risk of developing more serious drug abuse.