Smart cities use integrated information and communication technology in order to help their citizens and organizations deal with the challenges of urbanization, safety, and sustainability. Smart cities need complex forms of governance involving a great variety of actors. The aim of this study is to illustrate how elements of governance structures in smart city ecosystems evolve over time, and to understand in which way these elements enable or inhibit the success of such ecosystems in different phases of evolution. We draw on the ecosystem literature and the smart city literature to identify governance aspects relevant to projects with multiple stakeholders. We illustrate our framework with extensive empirical evidence from an in-depth single case study of a smart city initiative in The Netherlands. We find that the use of specific governance elements varies across the phases of evolution of the smart city ecosystem. In the initiation phase, governance structures aimed at strengthening the internal relations are key. In this phase, elements such as trust, commitment, and common goals are important as they help to create a common ground. In the growth phase, the ecosystem focuses on establishing external relations with other parties, such as competitors and suppliers. In this phase, governance elements such a co-creation strategy and a dedicated organization for promotion gain importance, as these elements facilitate communication with external parties.