Since 2002, the Network for the Early Warning, Investigation, and Surveillance of Healthcare-Associated Infections (HAIs) has enabled the five centers for the coordination and control of HAIs to conduct surveillance of healthcare-associated bacteremia (HAB) based on a standardized national protocol. Serving as a benchmark for the incidence and bacterial ecology of severe invasive nosocomial infections, this surveillance covers all departments and specialties in participating healthcare facilities (HFs). In 2004, the 286 participating HFs accounted for 117,630 beds (25% of all beds in France). The incidence rate of HAI acquired during inpatient stays in the HC was 0.45 per 1,000 patient-days. It was highest in intensive care units (3.85) and in cancer treatment centers (1.89). Catheter and urinary tract sites were the most common entry points (20.9% and 20.8%, respectively). The main microorganisms (MO) responsible for healthcare-associated infections were E. coli (20.5% of isolated MOs, of which 2.8% produced extended-spectrum beta-lactamase), S. aureus (18.1%, of which 41.4% were methicillin-resistant) and coagulase-negative S. species (14.5%). A death within seven days, regardless of cause, was reported in 11.9% of BN cases. It was more frequent when P. aeruginosa was isolated (21.5% of bloodstream infections caused by this organism). These results confirm those obtained in other European countries. Efforts must be prioritized toward the prevention of catheter-related bloodstream infections. The relationship between bloodstream infections and patient death should be the subject of future studies. (R.A.)