The Drug Use Monitoring in Australia (DUMA) program has been collecting information from police detainees on a quarterly basis in seven sites across the country since 1999 in order to help inform strategic responses to local drug problems. The 2003 data indicate that 57 percent of detainees had a previous arrest within the past 12 months; of these detainees with a previous arrest, 48 percent tested positive for heroin, methamphetamine, or cocaine. Another 20 percent of 2003 police detainees had a prior imprisonment term during the past 12 months and 4 percent had been imprisoned for a drug-related offense during the past year. Of all the 2003 detainees who had previous imprisonments, 54 percent tested positive for heroin, methamphetamine, or cocaine, while 75 percent of those who went to prison for a drug-related offense tested positive for these substances. A demographic profile of police detainees for 2003 is offered and reveals that 84 percent of detainees were males and only one quarter had a full-time job in the past 30 days. A comparison is offered of results from self-report data versus urinalysis data on drug use patterns; results show that police detainees are more likely to report past 30 days use and are more likely to under-report drug use within the past few days or at the time of arrest. Data are offered by type of drug and trends in recent drug use from 1999 through 2003 are analyzed. Methamphetamine use increased over the study period; heroin use decreased, and cocaine increased around the time of the heroin shortage and then fell back to normal levels. The relationship between illicit drug use and crime is explored; comparison data indicate few differences in the link between recent drug use and offense charges from 2002 to 2003. Tables, figures, references