Most American research considers the assimilation of the norms and values of a given profession to be the most important way in which that profession controls the socialization of its future members. This view of social control is based on a problematic pattern of socialization. Using the results of a research into the socialization of general practitioners, a different approach to this problem of social control is suggested that takes into account the specific manner of integration into the university-hospital structures and the ways in which future doctors gain access to the professional world. The hospital with its scientific logic is thus the chief instrument of social control, even though this control is limited by the very nature of the hospital: hospital training only partly controls the application of this scientific knowledge by general practitioners.