In this paper we study the motives behind sustainability strategy implementation and how the performance measurement system (PMS) is modified during different development stages in a municipal organization. We use a case study approach and focus on one of the greenest municipalities in Europe, Växjö municipality in Sweden. With empirical results supporting the existence of several phases during the implementation process, our research offers two important contributions. First, it provides additional insight in the set of motives for the use of PMS during different development phases. Main stakeholders, politicians and managers of municipal departments and municipality owned companies, have revealed several “layers” of motives, which have shaped the development of the PMS. Second, the research also show that the PMS has a noticeable symbolic importance in promoting and communicating the green strategy to citizens and businesses in the region.