This report explores the facilitators and barriers to care for vulnerable young people who use alcohol and other drugs and who have police contact. In particular, it investigates the role that police in inner-city areas of Sydney (New South Wales/NSW) and Melbourne (Victoria) have in relation to young people’s pathways in the health and welfare service system. The study draws on mixed methods data. These include: a review of relevant literature and policy documents; secondary analysis of two existing datasets describing vulnerable young people with police involvement, the Youth Cohort Study (YoCo) in Victoria and the Exposure and Transition Study in NSW; and N=64 in-depth qualitative interview data derived from clients of youth specialist AOD services aged 16-21 years who have had police contact (n=23), police staff (n=25) and youth AOD treatment service professionals (n=16). Analysis of these data aims to support the development of integrated diversion and treatment pathways for young people who offend, are eligible for diversion and/or may benefit from AOD treatment. The report provides implications that may be taken into consideration by policy makers and decision makers in government, particularly those that make decisions about service allocation and justice processes. The implications identified may also inform continued improvement of practice by police and service providers, as well as enhancing collaborative efforts between them.