Objectives Self-testing is an effective tool to bridge the testing gap for a number of infectious diseas-es; however, its performance using SARS-CoV-2 antigen-detection rapid diagnostic tests (Ag-RDTs) has not been systematically reviewed. We evaluated the accuracy of COVID-19 self-testing and/or self-sampling using Ag-RDTs to inform WHO guideline development. Methods: We searched multiple databases for articles evaluating the accuracy of COVID-19 self-testing or self-sampling through November 19th, 2021. Cohen’s kappa was estimated to as-sess concordance between self-testing/self-sampling and solely professional-use Ag-RDT results. Meta-analysis was performed to obtain pooled performance estimates compared to molecular testing. The QUADAS-2 and GRADE tools were used to evaluate quality and cer-tainty of evidence. Results: Of 12,946 publications, 19 were eligible; two reported on self-testing, while 17 studies as-sessed self-sampling only. Risk of bias was low (28.1%). Overall concordance with profes-sional-use Ag-RDTs (n=5) was high (kappa 0.92 [95% confidence interval (CI) 0.89 to 0.95]). Overall pooled sensitivity of Ag-RDT testing using self-testing/self-sampling was 72.0% (95% CI 62.4 to 80.0). Conclusion: COVID-19 self-testing/self-sampling exhibits reasonable performance and high concordance with professional-use Ag-RDTs. This suggest that self-sampling, at a minimum, can be offered as part of COVID-19 testing strategies, despite high heterogeneity among studies and the paucity of data.