The Drug Use Monitoring Australia (DUMA) project was introduced in 1999 to provide a focused monitoring of illicit drug use among criminal populations in New South Wales (NSW). DUMA was designed to measure the prevalence of illicit drug use among the criminally active, identify trends in drug markets, identify geographic variations in drug use, and explore the links between illicit drug use and other criminal activity. This bulletin draws and reports upon data from a sample of police detainees from two local area commands within Sydney, Bankstown and Parramatta and collected over the first 2 years of DUMA’s operation in NSW. Over the first 2 years of operation in NSW, 1,695 detainees were interviewed. The report begins with a brief overview of the DUMA methodology and than presents a summary of the sample characteristics that include: demographics, such as ethnicity, marital status, residence in past month, and source of income, and offense types. This is followed by an exploration of illicit drug use among detainees and illicit drug market trends. Major findings of the report covered: (1) factors associated with illicit drug use; (2) drug activity at time of arrest; (3) trends in illicit drug use; (4) Methadone use; (4) purchasing practices; and (5) perceptions of risk. The DUMA results continue to indicate a high prevalence of illicit drug use among police detainees, with over 70 percent of the sample indicating illicit drug use in the past 12 months. Urinalysis results show a decline in the use of heroin in the first half of 2001 and an increase in cocaine use during the same period. Purchasing practices varied according to the type of drug being purchased. Opinions on the risk in buying illicit drugs were divided, and the same pattern was found when asked on the risk of selling illicit drugs. Figures, tables, and references