The aim of the paper is to discuss the role of the line manager in implementing to plan, implement and evaluate successful organizational interventions using our experiences from the ARK-program. Earlier literature has shown that line managers have a major influence on an intervention’s outcomes (Nielsen, 2017; Saksvik, Nytrø, Dahl-Jørgensen, & Mikkelsen, 2002), however, there is a lack of knowledge about the managements’ role throughout the entire intervention process and how line managers are influenced by the context at different levels. We therefore discuss the line managers’ role within the five phase cycle of an organizational intervention, including preparation, screening, action planning, implementation and evaluation. We also introduce a more in-depth understanding of the context by using of the IGLO-model (Individual, Group, Leadership and Organizational level). Based on our knowledge and experience from the ARK-program we make some recommendations for (a) what the line managers need throughout the five phases in order to contribute to a successful intervention, and (b) on what the line manager has to provide in order to develop and implement a successful intervention process.