The aim of this point-prevalence study was to determine the prevalence of hospital-acquired infections (HAIs) by site of infection and the associated risk factors in a 'hospital at home' setting in Paris. All patients undergoing a care procedure with a risk of infection and who had been in home care for more than 48 h on the day of the survey (5 June 2000) were enrolled. A standard questionnaire was completed by nurses, midwives and family doctors. Overall, 6.1% of patients had at least one HAI [95% confidence intervals (CI): 3.7-8.5%] and there were 6.3 infections per 100 patients (infections/infected patients ratio: 1.04). The most common site of infection was the urinary tract (50.0%), followed by the skin (37.9%). Infection rates were 3.2% and 2.4%, respectively. Escherichia coli (29.4%), Staphylococcus aureus (29.4%) and Enterococcus spp. (17.6%) were the predominant micro-organisms. In multivariate analysis, the most significant independent risk factor was the presence of a urinary catheter (odds ratio= 15.9, 95%CI: 6.3-40.1, P< 0.0001). In conclusion, this prevalence study has provided a better understanding of the types of patient receiving 'hospital at home' care, an insight into risk factors for HAIs in home care, and a basis for improving surveillance and prevention. (C) 2004 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.