Since 2006, surveillance data have shown a decline in the incidence of Legionnaires' disease in France. This trend was confirmed in 2009, with 1,206 cases reported, corresponding to an incidence in metropolitan France of 1.9 per 100,000 inhabitants. The median age was 62 years, the male-to-female ratio was 2.9, and the case-fatality rate was 11.5%. The majority of cases were diagnosed by a urine detection test, and a strain was isolated in 220 cases (18%). Risk exposure was reported for 38% of cases. No outbreak (more than 10 cases) was identified in 2009. This summary of Legionnaires’ disease cases shows that the trend observed in recent years continued in 2009. However, the case fatality rate remains high and justifies maintaining awareness among all partners. The sources of exposure for cases, particularly sporadic community-acquired cases which constitute the majority of cases, must be better documented to enable the rapid implementation of preventive measures in order to sustain this downward trend. (R.A)