This paper try to analyze the relationships between the internal labour market and the peripheral workforce in the hospitals, mainly for low wage/ low skilled workers. It will put the emphasis on the one hand on the human resource management of the hospitals and on the various reasons and way by which they are articulating a core work force and a labour reserve army. It will also develop a very preliminary analysis of the biography of some workers, in order to grasp the relationship between the core work force and the periphery from the lifelong point of view of the workers. This could also help to understand if their has been some structural changes between the eighties and today.