The data in this report were collected as part of the Australian Institute of Criminology’s Drug Use Monitoring in Australia (DUMA) program, which is a quarterly collection of criminal justice and drug use information from police detainees at multiple sites across Australia. From January 2015 to December 2016, 4,400 adult police detainees were interviewed in Brisbane, Adelaide, Perth and Sydney (Bankstown and Surry Hills), most of them male (83%; n=3,647). Recent users reported consuming cannabis on average 15 out of the last 30 days before detention and rated the availability of cannabis at an average eight out of 10, while quality was given an average rating of seven out of 10. The price of cannabis was reported to be approximately $25 per bag. Recent users reported that the price of cannabis had remained the same compared to the three months prior to interview.