In this paper, I use a unique micro-database of 254,000 individuals distributed in 12 Spanish mining municipalities to explore the households’ decision-making processes regarding their children’s education. This database covers individuals living in municipalities in Asturias, Cantabria, the Basque Country, Huelva, Almería, and Murcia from 1877 to 1924. Focusing on around 42,000 children between eight and 18 years old, the findings show that living standards were a key component of human capital formation. Children in working-class families had considerably lower literacy levels than the offspring of upper- and middle-class families. Moreover, the analysis shows that there was a significantly greater gender gap among mining families working in open-pit mines than among other working-class families or those of underground miners. This difference lowered the wages of open-pit mining families which translated into a higher burden for daughters, hampering their human capital formation.