Abstract: The article presents the ways in which social functions, particularly cultural and/or symbolic ones, of the public library are related to social inequality. This analysis is product of the doctoral thesis La incidencia de la biblioteca en la reducción de las desigualdades sociales: el caso del Sistema de Bibliotecas Públicas de la ciudad de Medellín a partir del Acuerdo 079 de 2010 [The incidence of the library in the reduction of social inequalities: The case of the System of Public Libraries of the city of Medellin from Agreement 079 of 2010], which had the purpose of investigating, under an intercultural approach, the impact of the library on social inequalities, through the practices of reading, writing, and orality implemented in it. For the analysis presented in the article, an analytical-documentary analysis study was implemented, which used two research methods: Documentary and case study. Initially there is a brief introduction to the doctoral thesis and the methodology used. The conceptual understandings of theoretical referents regarding the library and its connection with cultural social functions are presented below. Next, an analysis of the empirical material from the case studybegins, situating the intentions of the public reading and writing policy in Medellín, and then analyzes the cultural functions of the public library in Medellín. Finally, as a closure, a section where some of the challenges that the city has in terms of culture and library is presented, as a result of contrasting the theoretical information with the empirical information.