The poster presents the preliminary results of a study on the costs and efficiency of water distribution utilities in Switzerland. Climate change, water scarcity and growing concerns about the performance of network industries are some of the elements that put pressure on water distribution utilities. Given those elements, an efficient management of the resource is fundamental to rise to the challenges that lie ahead. The aim of this study is thus to contribute to the ongoing debate concerning the definition and the comparison of the performance of Swiss water utilities by analysing their costs and efficiency, taking account of the influence of environmental factors.