Fifty-three heroin addicts, nineteen of them methadone treated, were asked about their use of flunitrazepam. Drug abuse began after a medical prescription in 50% of cases; flunitrazepam was taken per os, but also i.v. in 19% of cases. The mean daily dose was about 20 mg/day, often associated with other psychotropic drugs, alcohol, opiates or cocaine. Attention is focused on the amnesia and increased feeling of power (11% of cases), often resulting in serious violent offenses.