This study assessed the effect of an intervention designed to reduce the use of seclusion and restraint on reported episodes of patient-related violence on an acute inpatient psychiatric service. Results showed a significant decrease in the total number of episodes of seclusion and restraint between the 12 months before and after the intervention. However, the number of episodes of assault on patients and staff increased significantly. Efforts to decrease seclusion and restraint may be accompanied by an increased risk of harm to psychiatric patients and staff, and intensive safety monitoring and staff training should accompany all such efforts.