The Authors describe the survey's results aimed at quantifying the Haemophilus influenzae type b meningitis incidence rate in Italy. The survey collected all the cases of 1994 notified per region to the Ministry of Health; furthermore, regional incidence rates are compared and integrated with other data obteined from local ad hoc studies. The results obtained show a high incidence in the age group 0-2 years and a large discrepancy in the incidence rate between regions (from 0.0 to 16.8 cases per 100,000); furthermore, in the same age group, for a large amount of meningitis cases (18% of the total) the aetiological diagnosis was not successful; this phaenomenon is certainly one of the causes for the underestimation of the disease. The integration with data collected in longitudinal studies, increases largely the regional incidence rate, showing the highest rate in the Lazio Region (18.5 cases per 100,000). The Authors conclude by stressing the need to increase the cooperation between the Regional Health Authorities and the Ministry of Health, in order to obtain more reliable figures of the national incidence rates.