A one-day point prevalence of infection analysis was undertaken in 1417 intensive care units (ICUs) (10,038 patients) in 17 western European countries. The prevalence of ICU-acquired infection was 20.6% (2064 patients), representing almost half the cases of infection. Pneumonia was the most commonly reported infection (46.9%), followed by infection of the lower respiratory tract (17.8%), urinary tract (17.6%), and blood (13.0%). Staphylococcus aureus was the most frequently isolated organism (30.1%), followed by Pseudomonas aeruginosa (28.7%), coagulase-negative staphylococci (19.1%), yeasts (17.1%), and enterococci (11.7%). As a group, the Enterobacteriaceae were the most commonly isolated organisms (34.4%). The study also revealed that resistance to antimicrobial agents is common among Staphylococcus aureus, Pseudomonas aeruginosa, and coagulase-negative staphylococci.