Military training facilities and operational theatres, and the stressful activities undertaken in such settings, are unique. Military personnel living and working in these environments are at considerable risk of the acquisition and onward transmission of a variety of respiratory infections. While these generally cause mild illness, severe disease may occur with significant associated morbidity and, occasionally, mortality. Epidemic outbreaks among military personnel may have a significant detrimental impact on training schedules and operational effectiveness. The recognition of the burden of such illness among British military personnel, and the development of strategies required to prevent or limit negative impacts, can only be achieved through the use of comprehensive laboratory-based surveillance programmes.