, 18%-24%) over the 4-week study period. The greatest reduction was for combined infant and toddler visits (69%; 95% CI, 58%-79%); these did not recover the following year. However, during the SARS outbreak there was a large increase in the number of visits for respiratory illnesses in adults (61%; 95% CI, 46%-75%) and in teenagers (132%; 95% CI, 82%-182%). Conclusions: During the SARS outbreak, total ED visits fell. The relative decline was most notable for infants and toddlers. By contrast, there was an increase in respiratory illness-related visits for adults and teenagers. In 2004, the year following the SARS outbreak, visit patterns shifted toward baseline levels, but ED visits by infants and toddlers remained depressed.