In 2002, in the three departments of southwestern France, invasive meningococcal C infections were hyperendemic, with a rate nearly ten times higher than the national average (0.3 per 100,000). Other indicators suggested a risk of a new strain becoming established. The Minister of Health authorized a vaccination campaign for all children and adolescents aged 2 months to 20 years and for 20- to 24-year-olds living in group settings. Vaccinations were administered by general practitioners and public vaccination services. The target population was identified by the CPAMs and DDASSs, totaling 306,000 people in the Hautes-Pyrénées, Landes, and Pyrénées-Atlantiques departments. The CPAMs sent the individuals concerned documents containing a prescription form, a consent form, and a vaccine pickup form. Three data sources were used to assess vaccination coverage: the volumes of vaccines delivered to wholesale distributors, the number of vaccine doses dispensed by pharmacists, and surveys in primary and secondary schools. The data from wholesalers were of limited use. The estimated vaccination coverage (campaign coverage) based on data from pharmacists, relative to INSEE estimates, for the three departments 40, 64, and 65 is 69.2%, 65.8%, and 85.3%, respectively, for children aged 0–19. Surveys in elementary school classrooms measured total vaccination coverage (campaign coverage + pre-campaign coverage) at 94.1%, 91.6%, and 87.9%, respectively. In secondary school classrooms, coverage was 93.7%, 87.7%, and 87.1%, respectively. The meningococcal "C" vaccination campaign in these three departments, although carried out on an emergency basis, achieved good uptake among the population. A vaccination coverage rate of over 80% was achieved. (R.A.)