ORIENTATION: The negative environmental effects of single-use plastic shopping bags have prompted national governments to implement interventions to curtail their use. Plastic bag tax is gaining prominence as a single-use plastic shopping bag governance tool in several jurisdictions. RESEARCH PURPOSE: The primary objective of this study is to assess the efficacy of plastic shopping bag tax as a governance tool in South Africa by drawing lessons from Ireland and Denmark success stories. MOTIVATION FOR THE STUDY: This study contributes to the evolving debate on managing plastic bag litter with the objective of proffering long-term plastic bag litter management strategies. RESEARCH DESIGN, APPROACH AND METHOD: A quantitative case study methodology was employed in this study. South Africa, Ireland and Denmark qualified as units of analysis. A case study was appropriate for this study as it allowed for an in-depth, context specific analysis of the implementation of plastic bag tax. Document analysis in form of government and environmental reports was used to collected data. Thematic content analysis, which employed an inductive approach was used to analyse data. MAIN FINDINGS: Stakeholder acceptance, importance of a baseline assessment, proper tax governance, the necessity of continuously monitoring and enforcing the tax emerged as critical success factors. PRACTICAL/MANAGERIAL IMPLICATIONS: Consumer education, regular reviews, extended producer responsibility tax and improved transparency in the use of tax revenue are recommended as best practices to promote effective plastic bag tax implementation. CONTRIBUTION/VALUE-ADD: Effectiveness of the plastic bag tax should be assessed based on changes on volumes of plastic bag consumed, environmental quality and acceptance of the tax by key stakeholders such as manufacturers, retailers and consumers. Promotion of a circular economy in which discarded plastic bags can be reused for energy generation is recommended as a sustainable option.