||In the occupational risk prevention field, there is clear evidence that psychosocial or organizational problems are less focused than safety, hygienic or ergonomics aspects. May be because the risks are more difficult to identify, measure and evaluate, and also because it's a very sensitive field. According to European Survey of Enterprises on New and Emerging Risks, only 26% of companies in the 27 member states of the Union reported applying procedures to manage workplace stress. In Spain the situation is similar or worse. Of the small percentage of the companies that carry out specific studies on Occupational Risk Prevention, a much lower percentage carry out psychosocial risk interventions. The objectives of this research are to describe social practices of psychosocial risks evaluations; to analyze how the relationship between the agents (employers, workers, technicians, inspectors, outside consultants, etc. ) guides the evaluation process; to examine the influence of organizational context and the products (reports, letters, etc. ) in the process of evaluation and to identify, in the practices, how preventative measures are concreted, planned and implemented, and how this determines the usefulness of psychosocial risk assessment. This is an ethnographic study including participant observations and in-depth interviews on two organizations selected for the study. We observe, in the process of risk evaluation, actions: we identify recurring actions, variables in execution, constants in the sense, and that deploy from certain positions. Following this thinking we use notions of the theory of social practices of Pierre Bourdieu as a tool to think about the evaluation processes and their usefulness. From that perspective, we identify the interests of the field, the relative positions of the social agents, and strength and power relationships. This lead us to understand the practices as strategies implemented by the agents without necessarily being aware of it, in defense of their interests, which are evident in this kind of intervention.