The thesis From sustainability strategy to action in practice has been produced based on an interest in how sustainability strategies can be implemented by municipal employees in a specific practice. We are interested in the role municipalities must comply within the sustainable change movement, as these must be role models for sustainable development for the entirety of Danish society. That is why we are focusing specifically on Aalborg Municipality, which has previously stated itself as a lighthouse of sustainability. Based on social constructivist positioning and with a socio-cultural understanding of learning, this thesis examines how Aalborg Municipality translates their sustainability strategies into action among employees. We use Foucault (1999) inspired discourse analysis to examine respectively political sustainability discourses in Aalborg Municipality’s strategy, municipal employees' sustainability understandings, and what consequences these have in terms of converting strategy into action. The conversion from strategy to action is presented on the basis of Lundgren's (2006) theoretical concepts of formulation- and realization arena. The learning realization is analyzed on the basis of the constructed concept of practice-oriented sustainable action competence, which has theoretical references from Jensen and Schnack (1993) and Nygren and Fauske’s (2010) definitions of the action competence concept, and Læssøe’s (2020b) definition of the concept of sustainability. With Aalborg Municipality as the case, and the key informants in this thesis are the project manager from Center for Grøn Omstilling, representing the organizational level where sustainability strategies are formulated, and municipal employees who must realize the formulated strategies in practice. The project manager is interviewed in a semi-structured interview, and the employees, who represent two different administrations in Aalborg Municipality, are interviewed through two focus group interviews. A key finding is that the employees do not have knowledge of Aalborg Municipality's current sustainability strategy. This makes it difficult for municipal employees to develop sustainable action competence, as the lack of knowledge about the organization's ideological strategy makes it challenging for employees to work towards the same ideological purpose. Another finding is that language and action are closely linked, and that language can be both a contributor and a barrier to action.