Recent media coverage has raised awareness of the involvement of drugs, both licit and illicit, in the crime of date' or acquaintance' rape. The term date rape drug' has been coined and has been used to label a few speci®c drugs because of their alleged properties. These include ¯unitrazepam (Rohypnol), gamma hydroxybutyrate (GHB) and ketamine. Concerns over reports of ¯unitrazepam in connection with date rape' led to action by the manufacturer of Rohypnol ( ¯unitrazepam), F. Homan-La Roche Ltd. who undertook an educational campaign warning of the dangers of drug-assisted sexual assault, and changed their drug's formulation internationally to prevent its clandestine use. Despite the media interest, there has been little evidence and no systematic investigation to date of the incidence of drug use in the crime of sexual assault. The present study, from the USA, was therefore instigated to assess the extent to which dierent drugs were present in the urinalysis of samples supplied by victims of rape where drugs were allegedly involved. The study was so designed as to examine any changes over time in the patterns of drug use in sexual assault. Between June 1996 and May 1998, 1033 samples were tested. Nearly 20 dierent substances were detected among the 611 specimens that tested positive. Of these, 382 (37 per cent of all specimens) were positive for alcohol and 191 (18 . 5 per cent) were positive for cannabinoids. GHB was detected in 4 . 4 per cent of samples. Only six (50 . 6 per cent) specimens showed evidence of ¯unitrazepam, and four of those contained other substances including cocaine, alcohol and/or morphine. Thus, only 0 . 2 per cent of all samples were positive for ¯unitrazepam alone. These data clearly indicate that there is no evidence of widespread misuse of ¯unitrazepam in sexual assault. Alcohol remains the substance most frequently associated with this type of crime.