Introduction - For more than twenty years, the annual incidence rate of invasive meningococcal disease (IMD) in France has ranged between 1 and 2 cases per 105 inhabitants. Methods - Epidemiological surveillance of IMD relies on mandatory reporting and the characterization of invasive strains by the National Reference Center for Meningococci. Results - In 2009, 628 IMIs were reported, including 624 in metropolitan France (MF), corresponding to an incidence rate, adjusted for underreporting, of 1.1 per 105 inhabitants. The number of cases reported in 2009 decreased by 9% compared to 2008. The median age of cases was 15 years. Among IIM cases with a known serogroup in MF, 72% were serogroup B, 22% were serogroup C, 3% were serogroup W135, and 3% were serogroup Y. The number of reported serogroup B IIM cases has remained stable since 2005, while the number of serogroup C IIM cases decreased by 28% compared to 2006. Among the strains characterized by MLST (multilocus sequence typing), three clonal complexes were predominant: ST-41/44, ST-11, and ST-32. Severe clinical forms, primarily purpura fulminans, accounted for 28.5% of cases. The case-fatality rate for IIM was higher in the presence of purpura fulminans (19%) than in its absence (6%, p < 0.001). The case-fatality rate for IIM B and IIM C was 10%, with that of IIM C having decreased significantly compared to 2008 (17%, p < 0.01). Conclusion - Since 2005, the decline in the incidence of IIM in France, which was more pronounced between 2008 and 2009, is primarily linked to a decrease in the incidence of IIM C. In 2009, serogroup B remained predominant with a case-fatality rate identical (10%) to that of IIM C. (R.A.)