A mandatory reporting system has been set up in France on December 1st 1990. It aims at detecting clinical suspicions of BSE, i.e. animals showing evocative symptoms of the disease, among cattle aged two years or more. The diagnosis is confirmed by an histopathological examination of the brain. Between December 1st 1990 and July 4th 2001, 1123 clinical suspicions were recorded within the mandatory reporting system (851 non-confirmed cases, 233 confirmed cases and 39 samples non suitable for analysis). The analysis of the questionnaires shows that the recruiting of the suspicions is wider for animals for which the BSE diagnosis is difficult to rule out: animals suspected at the slaughterhouse, dead-on-farm animals, which is consistent with the objectives and the conditions of the clinical surveillance. Besides, none of the 23 clinical signs that had to be observed, taken separately, can neither predict nor rule out BSE diagnosis. These results may contribute to improve the efficiency of the mandatory reporting system, by increasing the disease awareness towards some categories of animals, and by emphasizing the fact that the clinical signs must be taken together and that repeated obsevations are needed before ruling out BSE