In 2010, the United Nations (un) acknowledged the human right to water and urged nation states to provide safe, clean, accessible and affordable drinking water, as well as sanita-tion for all. In 2012, the Mexican Constitution was reformed to guarantee this right. This paper examines how social inequality hinders the exercise of the said human right to water in San Jerónimo Tecóatl, a municipality located in the Mazatec Sierra in the State of Oaxaca. Data was gathered using quantitative and qualitative techniques: open-ended interviews, closed question-naires and workshops, along with tours throughout the Mazatec territory. The analysis focuses on three expressions of inequality: rurality, ethnicity and gender. Regarding the first, the paper shows that the potable water network was not established until the 1980s, and that to this day it provides a poor service, with water shortages for as much as three months per year. Second, the Mazatec territory was fractionalized and indigenous forms of organization regarding water man-agement were weakened due to the construction of dams and the professionalization of municipal governments. Third, the female population is the most affected by water shortages and has no decision-making power with regard to water management. The paper concludes that the social inequalities expressed in terms of rurality, ethnic and gender differences, hinder the full exercise of the human right to water in this area.