The use of restrictive practices in acute mental health settings is a contentious issue. Eliminating use of these practices in acute mental health settings is a goal in Aotearoa New Zealand and internationally. One way to support this goal is the use of training that teaches prevention of the use of restrictive practices. In Aotearoa New Zealand, there is a nationally consistent evidence-based training programme called Safe Practice Effective Communication (SPEC). This training focusses on de-escalation techniques, therapeutic engagement, use of trauma informed care principles, the use of cultural engagement as preventative strategies, and teaches the safe use of personal restraint as a last resort. Using a qualitative, descriptive, intrinsic case study, this research created an understanding of the unique development of a national approach for de-escalation and aggression management training called SPEC in Aotearoa New Zealand. Three phases of research were used to achieve this: (1) a review the current content of Safe Practice Effective Communication (SPEC) training compared to best evidence; (2) a description of how a decision was made to endorse the same de-escalation and aggression management workforce training programme across mental health and addiction services nationally; and (3) an in-depth review of how one district health board (DHB) moved from their existing approach to the agreed national training (SPEC). This research revealed that safety was central. Improving de-escalation and communication skills to prevent the use of personal restraint promotes safer outcomes for everyone. The use of personal restraint techniques that do not use any form of pain compliance and do not teach regular prone restraint reinforces safer outcomes. Having a nationally consistent workforce training programme across the country ensures that the same type of de-escalation and aggression management training can be taught and delivered. This creates efficiencies and makes it safer for everyone, as no matter what the setting, the same response will occur. Improving cultural safety and cultural responsiveness for the indigenous population, Māori as mana whenua, was identified as vital to effect better health outcomes for Māori. This emphasis on safety signifies a substantial practice change. This unique national implementation of SPEC occurred due to the unity amongst the clinical nurse leaders throughout the country to adopt SPEC; consistency was obtained through national agreement of the content and method of the training; and the momentum for change was signalled through the implementation processes demonstrated in one large metropolitan district health board. A common vision and strategic clinical nurse leadership were critical success factors for the national adoption and implementation of SPEC.