In June 2017 the process to take back into public hands the management of the integral water cycle in Valladolid was completed. The process has been long and not without complications, with intense social, political and legal debates, including several lawsuits from the current concessionaire, from some neighborhood associations and from the State Bar. Despite these obstacles, the procedure has received four favorable court sentences confirming the legality of the municipal action. This article presents some general ideas about remunicipalization processes in Spain, and their requirements and procedures, based on the search for efficiency and sustainability in the management of public services. There is also a review of the long procedure carried out by Valladolid City Council to take over the direct management of water supply and sanitation services in 2017, after the end of the concession contract awarded in 1997 for 20 years. This issue has been published as Volume 5, Number 1 of the WATERLAT-GOBACIT Working Papers (http://waterlat.org/publications/working-papers-series/). This is a special series of the Working Papers, titled “The struggle for democracy in Spain: grassroots initiatives to defend essential water services as a common good”, José Esteban Castro (Ed.), Edurne Bagué (Org.).