Data from two internet-based studies on NAUTI in hospitalized urological patients are presented together: the Pan European Prevalence (PEP) study, which was a 1-day prevalence study in November 2003; and the Pan Euro-Asian Prevalence (PEAP) study, which was carried out in November 2004. Overall, 93 and 101 hospitals from the two studies, respectively, completed the hospital questionnaires and provided patient information for the present study. NAUTI was diagnosed according to the Centres for Disease Control and Prevention (CDC) criteria in 727 of the 6033 patients hospitalized on study days in urological departments. The most commonly reported pathogen was Escherichia coli (31%), followed by species of Pseudomonas (13%), Enterococcus (10%), Klebsiella (10%), Enterobacter (6%) and Proteus (6%). Candida spp. and Pseudomonas spp. occurred significantly more frequently as causative agents in urosepsis than in other types of infections. The resistance of E. coli, Klebsiella and Proteus spp. was below 45% for the most commonly used antibiotics. Enterococcus spp. and Pseudomonas spp. however, had resistance rates above 70% to most antibiotics. A total of 56% of the hospitalized urological patients were receiving antimicrobial therapy on the study day; 46% for prophylaxis, 26% for microbiologically proven UTI, 21% for only clinically suspected UTI and 7% for other infections. The most commonly used antibiotics were fluoroquinolones (35%), cephalosporins (27%), penicillins (16%), aminoglycosides (15%), and co-trimoxazole (9%). Differences between countries and regions were highly significant. There is an urgent need for continuous surveillance of NAUTI and improvement of antibiotic policy to counteract the widespread increase of antimicrobial resistance.