In 2021 the Drug Use Monitoring in Australia program collected survey (n=2,223) and urinalysis (n=716) data from police detainees across Australia. Seventy-seven percent (n=553) of detainees who provided a urine sample for analysis tested positive to at least one type of drug, less than in 2020 (82%). Around half of the detainees tested positive to methamphetamine (50%) or cannabis (45%), one-fifth tested positive to benzodiazepines (18%) or opioids (18%), whereas very few tested positive for cocaine (2%) or MDMA (<1%). Self-reported past-month methamphetamine use was stable for most of 2021 until it declined in October–November, while past-month cannabis use increased in July–August. Nationally, methamphetamine and heroin each cost $50 per point on average, whereas cannabis cost $17 per gram.