Reporting meningococcal infections allows for the early implementation of preventive measures among contacts of confirmed cases. It also aims to determine the frequency, trends, and key epidemiological characteristics of these infections, as well as to evaluate the effectiveness of preventive measures. 384 cases of meningococcal infections (MI) were reported by the Departmental Directorates of Health and Social Affairs; the incidence of reported meningococcal infections was 0.66 per 100,000 inhabitants in 1997, representing a 10% increase compared to 1996. Taking into account a reporting completeness rate of 71%, the actual incidence can be estimated at 0.93 per 100,000. According to data available since 1945, the incidence rate of MI has reached its lowest level in recent years. France ranks among European countries with low incidence rates. In 1997, among family members of cases, 1,592 people received chemoprophylaxis and 189 received preventive vaccination; in community settings, 6,853 and 1,522 people, respectively, received these interventions.