Although some patterns of drug use among police detainees in 2005 remained similar to previous years, there were some notable changes. Cannabis use declined in all sites during 2005 compared with 2004. Despite this increase, however, cannabis still remains the most commonly used drug. Compared with 2004, the percentage of detainees who tested positive for heroin remained relatively stable at 12 percent for males and 17 percent for females; however, the proportion of opiate users who tested positive for a substance that contained an opiate metabolite unlikely to be heroin increased. The percentage of detainees who tested positive for methyl amphetamine remained relatively stable in 2005 compared with 2004, with 39 percent of females and 25 percent of males testing positive. Although the numbers of MDMA (ecstasy) users were small, the percentage of detainees who tested positive for MDMA continued a slow increase. In 2005, just over one-third of the detainees reported that at least some of their offending was drug-related. Detainees who were classified as drug dependents were arrested an average of three times in the past 12 months. Of the adult detainees who agreed to be interviewed, 81 percent (n=2,997) also agreed to provide a urine sample. The data presented in this paper was based on those adult detainees whose urine samples were tested. 1 table and 4 references