The author aims to study guns smuggling in Marseille during the French Third Republic. On one hand, the essay analyses the legislation which oscillated between complete liberalization and strict control, dividing the Republican period into three distinct chronological phases; on the other hand, the author outlines how the trafficking was organized, by dividing it, according to the market where it was directed, into traffics of local nature - destined to the urban milieu - and international - aimed at war zones where legal trade had been suspended. In the end, the author shows the case study of Marcel Seytres, an important arms trader from Marseille, reconstructing his smuggling.