BACKGROUND AND AIMS: Screening and brief interventions (SBI) delivered in primary health care (PHC) are cost-effective in decreasing alcohol consumption; however, they are underused. This study aims to identify implementation strategies that focus on SBI uptake and measure impact on: 1) heavy drinking; and 2) delivery of SBI in PHC. METHODS: Meta-analysis was conducted of controlled trials of SBI implementation strategies in PHC to reduce heavy drinking. Key outcomes included alcohol consumption, screening, brief interventions and costs in PHC. Predictor measures concerned single versus multiple strategies, type of strategy, duration and physician-only input versus that including mid-level professionals. Standardised mean differences (SMD) were calculated to indicate the impact of implementation strategies on key outcomes. Effect sizes were aggregated using meta-regression models. RESULTS: The 29 included studies were of moderate methodological quality. Strategies had no overall impact on patients' reported alcohol consumption (SMD 0.07;95%-CI -0.02-0.16), despite improving screening (SMD 0.53;95%-CI 0.28-0.78) and brief intervention delivery (SMD 0.64;95%-CI 0.27-1.02). Multifaceted strategies, i.e. professional and/or organisational and/or patient oriented strategies, seemed to have strongest effects on patients' alcohol consumption (p<0.05, compared with professional oriented strategies alone). Regarding SBI delivery, combining professional with patient oriented implementation strategies had the highest impact (p<0.05). Involving other staff besides physicians was beneficial for screening (p<0.05). CONCLUSIONS: To increase delivery of alcohol screening and brief interventions and decrease patients' alcohol consumption, implementation strategies should include a combination of patient, professional and organisational oriented approaches and involve mid-level health professionals as well as physicians. This article is protected by copyright. All rights reserved