BACKGROUNDQuality assurance programs (QAPs) are used to evaluate the analytical quality of a diagnostic test and provide feedback to improve quality processes in testing. Rapid diagnostic tests were used in both laboratory and non-laboratory settings to diagnose COVID-19, although varied in reported performance. We aimed to design and implement a QAP for antigen rapid diagnostic tests (Ag-RDTs) for COVID-19 in Cambodia, Lao PDR, and Papua New Guinea.METHODSInactivated SARS-CoV-2 material derived from cell culture of Wildtype, Delta, and Omicron isolates were used to manufacture 435 quality control (QC) panels (consisting of a single positive and negative sample) and 36 external quality assessment (EQA) panels for use across 15 sites in accordance with provided training and protocols.RESULTSIn total, 369 QC results and 112 EQA results were submitted by electronic reporting or paper forms by two countries. 19·3 % (34/176) positive and 99·5 % (192/193) negative samples were correctly reported in the QC, and 37·5 % (30/80) positive and 97·5 % (39/40) negative samples were correctly reported in the EQA.CONCLUSIONThis QAP demonstrates the importance of operator training and the design of QAP materials, which may have contributed to the high rate of false-negative interpretations in known COVID-19 positive samples. The implementation of this project, to our knowledge the first of its kind in the region and one of only a few globally, emphasised the importance of quality assurance principles, including non-laboratory community testing sites, to promote diagnostic quality for COVID-19 testing.