The study investigated the general population's perceived infectivity of asymptomatic and recovered severe acute respiratory syndrome (SARS) patients and factors associated with avoidance and discriminatory attitudes, including demographic background, SARS-related perceptions and emotional response to the SARS epidemic. A population-based survey was conducted in Hong Kong during 3 December 2003 through 4 January 2004; 475 Hong Kong Chinese adults participated in the survey. Perceptions of the infectivity and health conditions of recovered SARS patients and avoidance and discrimination towards them were measured. Of the respondents, 75.7% and 16.2%, respectively, believed that SARS could be transmitted via asymptomatic SARS patients and those patients who have recovered from SARS for 18 months; 72.7% of the respondents believed that the health of SARS patients would severely and permanently be damaged; 16.6% showed some tendency of avoiding recovered SARS patients and 35.7% expressed some sort of job-related discriminatory attitudes. Perceived infectivity of asymptomatic and recovered SARS patients, health "sequelae" and emotional distress from SARS were independently associated with avoidance and discriminatory attitudes. The study showed that misconceptions about the infectivity of asymptomatic and recovered SARS patients were common. Recovered SARS patients may also be facing avoidance and discrimination. (Contains 6 tables.)