The article presents a synthesis of research results from the study of Finnish water and sanitation services. It addresses the role of the public and private sectors in the provision and management of these services, placing emphasis on the importance of municipal authorities and consumer-managed cooperatives in rural areas. The paper discusses the wide range of options that can be found in the cooperation between public and private entities, which is a long-term historical characteristic of the country’s water and sanitation services sector. In the Finnish case, “private sector” in water and sanitation services refers mainly to a range of actors outside the public sector, most of which are small and medium scale providers of support services and manufacturers, and privately-run small cooperatives in rural areas. The article presents evidence of the levels of efficiency and quality of water and sanitation services, and offers a discussion of scenarios for the analysis of the main challenges facing these services, and suggesting likely trends and future developments.