During the second half of eighteenth-century, the walls of many churches, located on the royal roads between Potosi and Arica, were covered with mural paintings. This proliferation of pictorial programs could be linked to the discussion at the Synod of la Plata in 1771-1773. In some chapters of this Synod there are explicit references to Pope Benedict XIV's document about catechesis, as well as ideas about the sacred images proposed in treatises written after the Council of Trent. In this article, we will analyze five churches and their mural painting programs. In some ways, the wall paintings under study could be understood as the result of global Catholic policies and as a consequence of a complex network of circulation of ideas.Regular 2015FONDECYTFONDECYT