This report describes the case of an 18-year-old woman with meningococcal meningitis and purpura fulminans. Cerebrospinal fluid culture revealed Neisseria meningitidis serogroup-serotype-serosubtype C:2b:P1.2,5 as the pathogenic organism. Following treatment with cefotaxime and management of multiple organ failure, the patient survived without sequelae. To the best of our knowledge this report represents the first case of a meningococcal strain with a minimum inhibitory concentration of 1.5 mug/ml for penicillin, without beta-lactamase production, to be documented in France. The prevalence of meningococci with reduced susceptibility to penicillin is increasing. The emergence of such strains might represent a serious problem affecting the empirical antibiotic treatment of meningococcal disease.