To monitor the main community-acquired invasive bacterial infections in France, volunteer hospital laboratory scientists from the Epibac network report to the InVS cases of bacteremia and meningitis caused by Haemophilus influenzae, Listeria monocytogenes, Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus agalactiae, and Streptococcus pyogenes. With over fifteen years of validated data now available, national coverage of hospital admissions approaching 80% in 2006, and data collection completeness also around 80%, the Epibac database enables the analysis of trends and, more specifically, the impact of preventive measures—particularly vaccination—related to the pathogens under study. The analyses highlight the impact of vaccination against Haemophilus influenzae type b through a very rapid decline in the incidence of invasive infections caused by H. influenzae in the early 1990s, the decrease in the incidence of invasive infections caused by Listeria monocytogenes following control measures adopted in 1992, and the recent reversal of this trend, the impact of the recently widespread pneumococcal vaccination on the incidence of invasive S. pneumoniae infections in young children, and the reduction in the number of early invasive S. agalactiae infections following the adoption of preventive measures during pregnancy. The comparability of the results with those generated by other surveillance systems, where they exist, supports the validity of Epibac and the analyses performed using these data. This voluntary network constitutes a unique source for the surveillance of invasive bacterial infections that are not subject to mandatory reporting. (R.A.)