Since the recognition of the Human Right to Water and Sanitation by the United Nations in 2010, processes and debates have emerged regarding its effective implementation on an international, European and Spanish scale. Without doubt, the expression Human Right to Water is a key point of reference in debates about the management of urban water supply and sanitation services. However, the interpretations about the meaning of this Right are often excessively simplistic. On the contrary, the initiative promoted in Spain by various social groups and the Association of Public Operators of Water Supply and Sanitation Services (AEOPAS), called the Social Pact for Public Water, has moved in a different and enriching direction. This article presents a comparative analysis of the main aspects and implications of the notion of Human Right to Water approved by the United Nations and the Social Pact for Public Water developed in Spain. 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.).