Outbreaks of emerging and re-emerging infectious diseases are global threats to society. Planning for, and responses to, such events must include healthcare and other measures based on current evidence. An important area of infection prevention and control (IPC) is the optimal use of personal protective equipment (PPE) by healthcare workers (HCWs), including masks for protection against respiratory pathogens. Appropriate mask use during routine care is a forerunner to best practice in the event of an outbreak. However, little is known about the influences on decisions and behaviours of HCWs with respect to protective mask use when providing routine care. In this paper MBI's Ruth Barratt, Professor Ramon Shaban and Professor Lyn Gilbert argue that there is a need for more research to provide a better understanding of the decision-making and risk-taking behaviours of HCWs in respect of their use of masks for infectious disease prevention. Our argument is based on the ongoing threat of emerging infectious diseases; a need to strengthen workforce capability, capacity and education; the financial costs of healthcare and outbreaks; and the importance of social responsibility and supportive legislation in planning for global security. Future research should examine HCWs' practices and constructs of risk to provide new information to inform policy and pandemic planning.