The Dutch government has set an ambitious goal: by 2030, greenhouse gas emissions in the Netherlands should be 49% lower than they were in 1990.But even though geothermal energy is gaining recognition given the high heating demand in the Netherlands and its subsurface potential, implementation of this technology, especially in urban areas, is stagnating. A threefold-knowledge gap was identified in literature. First, it was identified that the viability of geothermal energy is case-specific. Therefore, the lack of knowledge about geothermal energy implementation in metropolitan setting results in uncertainty about the possible trade-offs of stakeholders and makes stakeholders wary of entering the market. Second, it is unclear how and to what extend regional norms, rules and regulations influence development of geothermal systems in urban areas after policy has been adopted. Third, significance of social acceptance is being discussed in a growing number of studies, however it is unclear how social acceptance may be operationalized in policy implementation research. Therefore, this thesis addresses the question how and to what extent institutions influence the success of the geothermal energy policy implementation process in urban areas in the Netherlands. The aim of this research is to consistently track institutions in geothermal energy policy implementation in urban areas in the Netherlands. For this purpose, a comparative case study has been designed to contrast the geothermal policy implementation process of two municipalities, The Hague and Nieuwegein, that share similarities in urban development, external context and type of geothermal technology, but differ in policy outcome. To structure the individual case analysis, a theoretical framework is developed that utilizes elements from the Multiple Streams Framework (MSF) by Kingdon and the Institutional Analysis and Development (IAD) Framework by Ostrom. From the findings it can be concluded that taking institutions into consideration influences the political and policy flow directly. The primary issues raised by the comparative analysis relate to social, ethical, and politically significant transactions. The lengthy policy implementation process was tainted by a general (mis)trust of the decisionmakers, and concerns were focussed about the equitable allocation of risks and rewards and the willingness to work together for a sustainable system.