The coronavirus that causes severe acute respiratory syndrome (SARS) is transmitted mainly via respiratory droplets. Typical presenting symptoms are akin to those of ordinary pneumonia. Young patients start with fever, chills, malaise, headache, or myalgia; cough and dyspnoea follow. Older persons and those taking corticosteroids may have neither fever nor respiratory symptoms. Exceptional suspicion is needed to identify SARS early in the illness. During an outbreak, even patients with low suspicion of SARS should be promptly isolated, and all contacts quarantined. Health workers need training in the use of appropriate barriers against droplets and other body fluids. Any fever cluster in patients or carers requires immediate action: discharges, visits, and transfers between wards and hospitals should be stopped. Halting hospital admissions and ten-day quarantine of suspected cases create wide buffer zones. To counter a possible resurgence of SARS, a system of prepared isolation and quarantine facilities is important.