A pilot surveillance program for hepatitis A was launched in 1999 by the French Institute for Public Health Surveillance (InVS) in collaboration with the Departmental Directorates of Health and Social Affairs (DDASS) and the Interregional Epidemiology Units (CIRE) in 14 departments of metropolitan France (Ardèche, Calvados, Charente-Maritime, Essonne, Gironde, Haute-Garonne, Haute-Loire, Haute-Savoie, Ille-et-Vilaine, Isère, Morbihan, Nord, Pas-de-Calais, and Puy-de-Dôme). The objectives of this surveillance were to detect clusters of cases at the departmental level, to estimate the incidence of acute hepatitis A, and to describe the characteristics of the cases. A case was defined as a person in whom anti-hepatitis A virus (HAV) IgM antibodies were detected in serum. Biologists from laboratories participating on a voluntary basis reported cases to the public health inspector (MISP) at the DDASS using a form, a copy of which was also sent to the prescribing physician; the latter then sent the form, completed with clinical and epidemiological information, to the DDASS. These forms were analyzed "in real time" at the DDASS to identify clusters of cases. Data entry was performed using an Epi-Info application developed for this purpose. A report was distributed quarterly by the DDASS or CIRES to the participating laboratories and physicians. The system’s ability to detect clusters, its simplicity, acceptability, sensitivity, and responsiveness were evaluated in 2001 to make recommendations regarding its future development. The authors present here a summary of the results of this evaluation. (R.A.)