BACKGROUND:Unhealthy alcohol use involves a spectrum from hazardous use (exceeding guidelines but no harms) through to alcohol dependence. Evidence-based management of unhealthy alcohol use in primary health care has been recommended since 1979. However, sustained and systematic implementation has proven challenging. The Continuing Quality Improvement (CQI) process is designed to enable services to detect barriers, then devise and implement changes, resulting in service improvements. METHODS:We conducted a systematic review of literature reporting on strategies to improve implementation of screening and interventions for unhealthy alcohol use in primary care (MEDLINE EMBASE, PsycINFO, CINAHL, the Australian Indigenous Health InfoNet). Additional inclusion criteria were: (1) pragmatic setting; (2) reporting original data; (3) quantitative outcomes related to provision of service or change in practice. We investigate the extent to which the three essential elements of CQI are being used (data-guided activities, considering local conditions; iterative development). We compare characteristics of programs that include these three elements with those that do not. We describe the types, organizational levels (e.g. health service, practice, clinician), duration of strategies, and their outcomes. RESULTS:Fifty-six papers representing 45 projects were included. Of these, 24 papers were randomized controlled trials, 12 controlled studies and 20 before/after and other designs. Most reported on strategies for improving implementation of screening and brief intervention. Only six addressed relapse prevention pharmacotherapies. Only five reported on patient outcomes and none showed significant improvement. The three essential CQI elements were clearly identifiable in 12 reports. More studies with three essential CQI elements had implementation and follow-up durations above the median; utilised multifaceted designs; targeted both practice and health system levels; improved screening and brief intervention than studies without the CQI elements. CONCLUSION:Utilizing CQI methods in implementation research would appear to be well-suited to drive improvements in service delivery for unhealthy alcohol use. However, the body of literature describing such studies is still small. More well-designed research, including hybrid studies of both implementation and patient outcomes, will be needed to draw clearer conclusions on the optimal approach for implementing screening and treatment for unhealthy alcohol use. (PROSPERO registration ID: CRD42018110475).