Introduction: Over the past ten years, the annual incidence of invasive meningococcal disease (IMD) in France has ranged from 0.90 to 1.60 cases per 100,000 inhabitants. Neisseria meningitidis serogroups B and C account for approximately 90% of cases. Methods: Surveillance of IMIs is based on mandatory reporting and strain characterization by the National Reference Center for Meningococci (Institut Pasteur, Paris). Results: In 2012, 559 cases of IIM were reported, including 547 in metropolitan France, representing an estimated incidence rate of 0.94 per 100,000 inhabitants. This rate was comparable to that of 2011. The median age was 18 years. Of these cases, 549, or 98% of reported cases, were biologically confirmed. The serogroup was determined for 539 cases: 68% were serogroup B, 18% serogroup C, 7% serogroup W, and 6% serogroup Y. Fulminant purpura was reported in 22% of patients. The case-fatality rate was 8%. An increase in the incidence of serogroup C IIM was observed in 2012 among children under 1 year of age and adults. Two clusters of serogroup B IIM occurred in the Pyrénées-Atlantiques and in Alsace. Conclusion: In 2012, serogroup B remained predominant, with various strains—including two hyper-invasive genotypes—circulating in two regions. An increase in IIM W was identified in connection with the importation of a clone from sub-Saharan Africa, and the proportion of IIM Y remained higher than what was observed prior to 2010. Since 2010, a trend toward an increase in the incidence of IIM C has been observed in age groups not targeted by meningococcal C vaccination (under one year and over 25 years). Vaccination coverage, which remains insufficient, has not allowed for the establishment of herd immunity. (R.A.)