The dissertatiin analyses the Liga pela Moralidade (League for Morality) as a result of the lay Catholic militancy existing in Rio de Janeiro, between 1917-1926. The ways os establishing itself as an active association for a moral sanitation os the city and the means of entretainment existing between the years highlighted. The Liga pela Moralidade arose after the reorganization os Catholic militants  and social doctrine, an experience of organizing youth in favor of Catholic ideals that were propagated in circles and events of a religious nature, but that did not have the active participation of clerics or identities linked to the Holy See.