Introduction - A national prevalence survey of infections was conducted in France in 2006–2007 by the Observatory of Infectious Risk in Geriatrics (ORIG). Our objective was to estimate the prevalence rates for all infections combined and the rates of upper and lower respiratory tract infections, by region and by study phase. Methods - This was a national, cross-sectional, periodic, one-month descriptive survey including all residents aged 65 and older in participating facilities. The infections considered were classified as confirmed cases (MacGeer definitions) and probable cases (Orig definitions). Results - 44,870 residents in 577 facilities were included. The mean age was 86 years [95% CI 78–92], the female-to-male ratio was 3, and 49% of residents were dependent (GIR 1 or 2). The overall prevalence rate of infections was 11.2% [95% CI 10.9–11.5]. Prevalence rates for all infections ranged from 4.4% [95% CI 1.2–7.6] to 16.6% [95% CI 13.9–19.3] depending on the region (p<0.0001). Conclusion - Given the existing literature, the study revealed a high prevalence rate. However, it is highly likely that this rate is significantly underestimated. (R.A.)