The spread of severe acute respiratory syndrome (SARS) in 2003 was largely driven by hospital-associated transmission where health care workers experienced the largest burden of disease. In attempting to improve occupational health and infection control procedures to prevent occupationally acquired infections in health care workers, it is important to examine the perceptions of those workers who are expected to adhere to specific policies. The authors conducted 15 focus groups of health care workers representing seven different job classifications in two Canadian provinces where SARS outbreaks occurred in 2003 using a theoretical framework which divided factors associated with self-protective behaviour at work into organizational, environmental, and individual factors. Content analysis of these discussions revealed that workers placed more importance on organizational factors than environmental and individual factors. The results are similar to those of a recently completed literature review of this subject, and should be considered when developing new occupational health initiatives to protect health care workers from existing or emerging respiratory tract infections.