A plethora of bullying prevention programmes and practices have been developed, with their efficacy evaluated in research trials. However, it is evident that both research and societal discussions have placed far less emphasis on the implementation and sustainment of these programmes under real-life conditions. Falling short on program implementation may jeopardize the potential effectiveness of the programmes. Recent studies have highlighted various factors, such as school resources, leadership, human resource management, staff training, and commitment, all of which can either fuel or hinder program sustainment (Herkama et al., 2022; Pearce et al., 2022; Sullivan et al., 2021). Furthermore, there is a recognized need for implementation support to enhance the effectiveness of bullying prevention efforts in the school context (Cross et al., 2019; Herkama et al., 2024a). However, evidence-based models for providing schools with implementation support are currently lacking. To fully benefit from bullying prevention programmes and practices and utilize their potential, greater attention should be directed towards implementation. This chapter sheds light on the implementation of bullying prevention programmes from various perspectives by introducing three examples, highlighting the critical role of effective implementation in maximizing their impact and sustainability.