Product differentiation and market segmentation : the example of French beef meat. The beef meat supply chain recently underwent a major exogenous shock : the publication of the possible transmission of the Bovine Spongiform Encephalopathy (BSE) agent to human led to a rapid and extended change in the relationship between the different protagonists in the whole supply chain. For the consumers the consequence of this evolution was the sudden appearance of several distinctive judicious labels (Viande Bovine Française -VBF, Critères Qualité Contrôlés -CQC) in order to reassure and advise them while purchasing. The purpose of this paper is to analyse the process of segmentation of the fresh beef meat market. In the first part, the authors make a brief inventory of the supply chain before the crisis. They show that this supply chain presents some characteristics (heterogeneity of the upstream product, low added value of the processing industry ) which explain why the vertical differentiation of the beef is weak. The vertical differentiation concerns only very limited market segments and can use collective labels (Label Rouge, Bœuf Verte Prairie) or private labels (such as Charal, a meat packer's brand with great notoriety) : both generate a guarantee on the product tenderness. Then, the authors propose an analysis of the vertical differentiation of the product after the BSE crisis in which they show that this differentiation is mainly based on a collective brand (CQC) developed by the inter professional body and based on the communication of reliable information to consumers (reliable because based on controlled regulation). This communication focuses on the product safety and is only possible because of an organisational innovation present in the whole supply chain (i.e. breeders and meat packers). This collective designation is used jointly with private brands, mainly developed by modern retailers, who inform about the upstream supply chain practices. Lastly, the analysis of the reasons of this rapid diffusion of the vertical differentiation of the beef leads the authors to suggest a new configuration of the beef shelf for the future. On this shelf, a product, which will offer only health guarantee, will be found next to differentiated products with retailers' brand names. These brands will adopt or not the collective signature CQC. The industrial brands mainly relate to the convenient goods market (such as minced meat and vacuum-packed fresh meat for example).