Introduction: Cooperation is key to provide integrated dementia care. However, different kinds of (personal and organisational) interests will affect collaboration in integrated dementia care (IDC) networks. Hence, it is crucial to understand how interests influence relations in IDC-networks in order to shape future policies. Methods: A sequential mixed methods single case study design was used, in three phases: a Social Network Analysis (SNA) based on data from questionnaires (n = 24–26), explorative interviews with network partners (n = 14) and a focus group with network coordinators (n = 7) to explore the conceptual generalisability of the single case of the IDC-network. Results: The SNA revealed that highly connected organisations were often established care organisations that deliver case management, while smaller care organisations or welfare organisations tend to be less connected. Care-related, strategic, and financial interests influence participation of organisations in the IDC-network, while personal intrinsic motivations determine a representative’s contribution to the network. Especially conflicting interests strongly influence the network structure. Discussion and conclusion: We conclude that conflicting interests in IDC-networks stand in the way of reaching the collective goal of an IDC-network, i.e., optimising the wellbeing of people with dementia and their informal caregivers in the region. Thus, IDC-networks should act to manage, resolve and prevent disputes arising from conflicting interests.