There are very few studies investigating the work nurses do in prisons. Based on data stemming from a research in Psychodynamics of Work and a literature review, this paper describes nursing practices in a Canadian penitentiary institution. Three male nurses and two female nurses participated in three two-hour long focus group sessions. Central sources of pleasure that emerged from the focus groups were the scope of nursing care practice ; the autonomy and collaboration with physicians; nursing care practices devoid of moral value judgments, the humanitarian approach, caring and the wish to make a difference in the lives of the inmates ; the pride connected to this unusual professional context, and the recognition by peers and inmates. The main sources of suffering on the other hand were the feeling that rehabilitation was more an ideal than reality ; the paradox of providing both care and safety ; the scary characteristics of working alone ; the fear of lawsuits, and the feeling of being observed continuously. The resulting data we discuss show the issues of a certain dissociation that exists between the patient and the inmate, the fear of contamination of a healthcare nursing identity by the place of practice, but also the feeling of plenitude and sublimation. The conclusion stresses the tension that exists between security and caring, distance and proximity.