The effectiveness of “the lockout policy” integrated within a broader police enforcement strategy to reduce alcohol-related harm, in and around late night licensed premises, in major drinking precincts is examined. First response operational police (n = 280) records all alcohol and non–alcohol-related incidents they attended in and around late night liquor trading premises. A before and after study design is used, with police completing modified activity logs prior to and following the introduction of the lockout policy in two policing regions: Gold Coast (n = 12,801 incidents) and Brisbane City/Fortitude Valley (n = 9,117 incidents). Qualitative information from key stakeholders (e.g., police, security staff, and politicians; n = 20) is also obtained. The number of alcohol-related offences requiring police attention is significantly reduced in some policing areas and for some types of offences (e.g., sex offences, street disturbances, traffic incidents). However, there is no variation for a number of other offence categories (e.g., assault). Interviews with licensees reveal that although all were initially opposed to the lockout policy, most perceived benefits from its introduction. This study is the first of its kind to comprehensively examine the impact of a lockout policy and provides supportive evidence for the effectiveness of the lockout policy as integrating positively with police enforcement to enhance public safety in some areas in and around late night liquor trading premises.