A survey of adult patients 19 years of age and older was conducted in February 2002 in hospitals across Canada to estimate the prevalence of healthcare-associated infections (HAIs). A total of 5750 adults were surveyed; 601 of these had 667 HAIs, giving a prevalence of 10.5% infected patients and 11.6% HAIs. Urinary tract infections (UTI) were the most frequent HAI, shown by 194 (3.4%) of the patients surveyed. Pneumonia was found in 175 (3.0%) of the patients, surgical site infections (SSI) in 146 (2.5%), bloodstream infections (BSI) in 93 (1.6%) and Clostridium difficile-associated diarrhoea (CDAD) in 59 (1%). In this first national point prevalence study in Canada, the prevalence of HAI was found to be similar to that reported by other industrialized countries.