Between 2016 and 2018, an evidence-based strategy for reducing conflict and violence—the Safewards Model—was implemented in two locked wards of an acute psychiatric hospital in Berlin/Germany. The implementation process lasted 12 months and was evaluated in several ways: First, frequency and duration of coercive measures applied during a period of 10 weeks before and 10 weeks after the implementation period was assessed through routine data. Second, a questionnaire survey regarding ward atmosphere and job satisfaction was conducted among patients and staff before and after the implementation of the Safewards Model. Third, staff was asked regarding the amount of practical implementation of each Safewards intervention after the end of the implementation period through a questionnaire. Fourth, an independent researcher scored on how well the wards adhered to the original Safewards Model. The case study outlines a pre–post mixed-method research approach in a clinical mental health setting. It discusses gained experiences and challenges as well as limitations of implementation studies of clinical interventions. The case study is useful for students and early career researchers in medicine, psychology, social sciences, and (public) mental health.