Highlights from the report include: (1) of the total sample of almost 13,000 respondents, around 13 percent had used prescribed benzodiazepine in the previous week/fortnight; (2) almost 18 percent of the Drug Use Monitoring in Australia (DUMA) program sample had used benzodiazepines in the previous month and 15 percent had used illegal benzodiazepines in the previous 12 months; (3) benzodiazepine use was marginally more likely to be found in combination with amphetamines than with heroin; (4) female detainees were more likely to have used most drugs than male detainees and more commonly used benzodiazepines and heroin and combinations; (5) the extent of self-reported benzodiazepine dependence was much lower than that for heroin; and (6) the characteristics of illegal benzodiazepine users were similar to those of other illicit drug users. Much of the research into benzodiazepine misuse has been conducted with intravenous drug users (IDUs) or methadone patients. This analysis investigates the prevalence of legal and illegal benzodiazepine use and harms in male and female police detainees, using self-report data from quarterly data collections, under the DUMA program, in four sites over 7 years (1999 to 2005). Tables, figure, references