Over the past few years, clinical research has developed considerably. To achieve adequate quality standards in its design and management, it was necessary to set up dedicated and qualified multi-professional teams, made up not only of medical personnel. This has led to the emergence of new professional roles, such as that of the research nurse (clinical research nurse, study nurse or clinical trial nurse). While in Europe this professional role is defined, in Italy it has started to assert itself only recently, with a profile linked mainly to practical rather than managerial tasks. The role is not yet recognized at institutional level and is not registered. The goal of our research was to understand how many research centers can rely on the presence of a research nurse in their staff and what was the research nurse's contribution to achieving the satisfaction of patients enrolled in clinical studies and on the work of the research team.