As of 23 March, 2003, 11 cases of SARS have been reported in Canada. Three patients had travelled to China, including Hong Kong SAR. The remaining eight had a history of close contact with cases. There have been three deaths. To date, evidence for human metapneumovirus has been found in six cases; further studies are ongoing to determine whether this virus is the causative agent of the SARS or whether other, so far undetected, pathogens are responsible. Public health measures are being implemented at the local, provincial, and national levels to identify new cases and prevent secondary transmission of SARS.