The process of implementing mental health promotion interventions is considered in this chapter. An overview is provided of current implementation frameworks and strategies and mental health promotion implementation research, highlighting why implementation is important and what we know from studies that have been carried out to date. The role of collaborative practice and intersectoral partnerships in implementing mental health promotion is discussed. Drawing on the literature, a number of implementation factors that are critical to effective partnership working are examined. Recommendations for supporting quality intervention implementation are outlined.