The Covenant of Mayors has secured the commitments of over 5400 European Cities (as of December 2013) to achieving the European Union 20-20-20 climate change mitigation targets by 2020 through action at the local level. Due to the youth of the initiative, few experiences have been reported in the academic literature. We study the development of the Sustainable Energy Action Plan (SEAP) in the city of Girona (Catalonia, Spain) to analyse the opportunities and challenges this process may present in a small- to medium-sized, compact Mediterranean city. This knowledge can provide information to local authorities in similar municipalities, technical teams and decision-makers at the European level interested in enhancing the performance of such plans in the future. In this article, we explain how the SEAP was developed in Girona, the main results and proposed actions, and discuss the main setbacks. We conclude that an overarching European oversight organism is advisable to coordinate and aid local efforts.