Executive summary The role of face masks in the control and prevention of COVID-19 remains an issue of debate. Prior to COVID-19, most studies assessing the effectiveness of face masks as a protective measure in the community came from studies on influenza, which provided little evidence to support their use. Assessment of the evidence The evidence regarding the effectiveness of medical face masks for the prevention of COVID-19 in the community is compatible with a small to moderate protective effect, but there are still significant uncertainties about the size of this effect. Evidence for the effectiveness of non-medical face masks, face shields/visors and respirators in the community is scarce and of very low certainty. Additional high-quality studies are needed to assess the relevance of the use of medical face masks in the COVID-19 pandemic.