From 1855 on, the local police in Paris intensified its surveillance of all activities linked to the production and commercialisation of obscenities. This commercial activity inherited from the Ancien Regime had been covertly growing, despite its illegality, since the beginning of the century. The industrialisation of the production of obscenities in the middle and at the end of the 19th century represented a source of increasing anxiety for the public authorities and all enterprising moralists. Even as French society increasingly witnessed the benefits of the Industrial Revolution and its mass diffusion, the growing distribution of obscenity through its commercialisation transformed it into a modern industry. Through focusing on the development of its Parisian industry, this historical study enables the understanding of how obscenity became a form of mass culture between 1855 and 1930.