Biosecurity measures are of major importance in the control of infectious diseases. The objective of this study was to classify pig herds on the basis of the implementation of biosecurity measures. Herd included in the study exhibited different Porcine Reproductive and Respiratory (PRRS) statuses: positive, under control protocol, recently negative or negative for a long time. A survey was carried out to describe biosecurity measures actually implemented in 58 herds from three areas in Western France in which PRRSv prevalence was heterogeneous. Several variables were established to describe biosecurity and a score was assigned for each variable. The variables were analysed using a principal component analysis followed by an ascendant hierarchic classification. Four groups of herds were distinguished with biosecurity status ranging from high to low. The PRRSv status was significantly associated with the biosecurity level; herds in which a PRRs control plan was currently or had recently been implemented exhibited a higher level of biosecurity. These results suggest that these farmers were more aware of the need for biosecurity when they were involved in control plans