This article centers on the persistent notion that female domestics are vulnerable to prostitution. Focusing on Vienna in the last decades of the nineteenth century, the article highlights the underlying fallacies of this notion. The 1810 Vienna Servant Code created a system of policing that made it easier for officials to collect data on maidservants. Compounded by problems in classification, maidservants seemed to form a major contingent in police prostitution data. The data enabled physicians to justify extending their authority over the private lives of a swelling population of occupationally diverse working-class migrant women in fin-de-siècle Vienna.