This paper reports the results of a study on the identification and management of violence in a psychiatric ward and in the psychiatric emergency unit of a Quebec hospital. The purpose of this exploratory and descriptive study was to examine the perceptions and strategies of patients and nurses for identifying and managing patient aggression and violence. The results show that the type of setting influences the way aggressive behavior issues are perceived and managed. The types of behavior deemed aggressive or risky also vary between the two units. Moreover, patients and nurses are similarly described by all participants as potentially violent and potentially being victims of violence. The prevention of aggression and violence remains a significant challenge in psychiatric nursing, where administrative and environmental constraints, the growing complexity of clinical profiles, divergent interprofessional approaches to care, and collective feelings of apprehension and vulnerability interact.