The aim of this study was to identify herd-level factors associated with the presence of cows infected by Mycobacterium avium subspecies paratuberculosis (Map) in dairy herds. Farm-management data were collected in 192 dairy herds located in western France according to a specific questionnaire administered during a farm visit from April to July 2003. Herd-status to Map-infection was defined depending on the presence (Map-positive) or the absence (Map-negative) in the herd of at least one positive-tested (ELISA, faecal culture (FC), PCR or Ziehl staining) lactating cow, aged more than 24 months. Logistic regression was used to quantify the relationships between herd-status to Map and farm-management factors. Factors associated with an increased risk for a herd of being Map-positive were cattle purchase (RR=1.60), late separation of the calf from its dam with possible suckling (RR=1.30), systematic distribution to calves of their dams' colostrum (RR=1.44), non hygienic milk supply (one bucket for several calves and/or cleaned less than once per day) (RR=1.24), long lasting bulk milk supply to the calves (RR=1.40), possible long-lasting contact of calves (RR=1.33) and heifers (RR=1.20) with adult cows, and absence of cleaning and disinfection procedure in the cows shed (RR=1.24). These results, which are in agreement with previous findings, suggest that main measures to prevent Map-infection must rely on calf care and on purchase of presumably non-infected cattle.