The objective of this work was to study hospital nurses' perceptions of pubic health based on a pedagogical exercise. A qualitative study, lead by students of a training institute for nursing care (IFSI), was conducted using semi-directed interviews of hospital nurses from different departments of a provincial hospital. The main results show that for one-third of the nurses interviewed, the hospital is not a setting for public health practice. In terms of their definition of public health, it is closely linked to the concept of prevention, with primarily individual approaches. This definition is very close to the public health activities that they conduct at the hospital and which are centred on information and disease prevention, on education related to pathologies and the relationship between the provision of care and listening to the patients and their families. Few nurses place their public health activities within the scope of the areas of hospital cleanliness, the welcoming of the patients, the organisation of services, and the improvement of the quality of care. The potential tracks which have emerged from this work lead to the need for the strengthening of training in patient education, in the hospital's work networking with external partners, and in better development of public health activities undertaken in the hospital setting.