Background: Intersectoral action is often presented as essential in the promotion of population health and health equity. In Norway, national public health policies are based on the health in All Policies (HiAP) approach that promotes whole-of-government responsibility. As part of the promotion of this intersectoral responsibility, planning is presented as a tool that every Norwegian municipality should use to integrate public health policies into their planning and management systems. Although research on implementing the HiAP approach is increasing, few studies apply a planning perspective. To address this gap in the literature, our study investigates how three Norwegian municipalities experience the use of planning as a tool when implementing the HiAP approach. Methods: To investigate planning practices in three Norwegian municipalities, we used a qualitative multiple case study design based on face-to-face interviews. When analysing and discussing the results, we used the dichotomy of instrumental and communicative planning approaches, in addition to a collaborative planning approach, as the theoretical framework. Results: The municipalities encounter several dilemmas when using planning as a tool for implementing the HiAP approach. Balancing the use of qualitative and quantitative knowledge and balancing the use of structural and processual procedures are two such dilemmas. Other dilemmas include balancing the use of power and balancing action and understanding in different municipal contexts. They are also faced with the dilemma of whether to place public health issues at the forefront or to present these issues in more general terms. Conclusion: We argue that the dilemmas experienced by the municipalities might be explained by the difficult task of combining instrumental and communicative planning approaches because the balance between them is seldom fixed.