In France, a national prevalence survey (ENP) of healthcare-associated infections (HAIs) has been conducted every five years since 1996. It is organized by the Network for Alert, Investigation, and Surveillance of Healthcare-Associated Infections (Raisin), a partnership between the French Institute for Public Health Surveillance (InVS) and the five Centers for Coordination of the Fight Against Healthcare-Associated Infections (CClin). This is a “single-day” survey offered to all public and private healthcare facilities; it includes all patients except those hospitalized on the day of the survey, in outpatient clinics, or receiving home hospitalization. The objective of this analysis was to describe the prevalence of HIs in the population of patients aged 65 and older. Of the 358,353 patients included in this survey, 199,716 (55.6%) were aged 65 and older. They were hospitalized primarily in general hospitals (CHG: 42.5%) or regional or university hospitals (CHRU: 17.1%). In this population, the prevalence of infected patients was 6.1% (3.5% among those under 65). The three most common anatomical sites were urinary tract infections (prevalence: 2.45%), pneumonia (0.94%), surgical site infections (0.77%), and skin or soft tissue infections (0.71%). The three most frequently isolated microorganisms were Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The decline in the prevalence of infected patients between 2001 and 2006 was estimated at 16% among patients aged 65 and older, a greater decrease than that observed among all included patients, suggesting an impact of programs to combat nosocomial infections in this population. However, the prevalence of nosocomial infections remains high in long-term care and rehabilitation settings and requires the implementation of specific studies and action programs in this sector of care. (R.A.)