Severe acute respiratory syndrome (SARS) is a recently described infectious entity with salient features of fever, headache and malaise, with rapid progression to pneumonitis. The etiology of SARS is likely a novel coronavirus. During the winter of 2003, an outbreak of SARS involving several hospitals occurred in Toronto, Canada. We describe a patient post liver transplant who contracted SARS and died during the outbreak, with subsequent infection of family and several health-care workers. A novel coronavirus was detected in respiratory specimens by PCR. Due to the potential severity of SARS in transplant recipients and the large number of cases of SARS in the community, in order to avoid transmission of SARS from a donor, we developed guidelines for SARS screening of organ donors. A screening tool based on potential hospital SARS exposure, clinical symptoms, and epidemiological exposure was used to stratify donors as high, intermediate or low risk for SARS. As SARS spreads throughout the world, it may become an increasingly significant problem for transplant patients and programs.