In the sixteenth century, the Ottoman central administration started to adopt and implement a series of new measures to regulate urban planning, maintain hygiene in urban spaces, and develop a system of central health administration. Istanbul served as the major venue for these new regulations and remained the prime recipient of the services that grew out of this institutionalization. For example, it was at that time that graveyards and slaughterhouses were systematically moved outside the city walls and littering was severely banned. Although these new services started as ad hoc regulations for preempting emergent situations (epidemic diseases, earthquakes, fires, etc.), they gradually became systematized through the course of the century to constitute the basis of an early form of “public health” organization in the Ottoman Empire. What is most interesting is that these measures were formed and put into practice at the same time that new medical notions (especially with regard to disease transmission) started to find their way into the scholarly discussions of Ottoman medical elite in the second half of the sixteenth century. These notions, which were fast embraced and canonized in the Ottoman medical literature, were also accepted as a sound basis of legal theory about proper conduct pertaining to bodily cleanliness and urban health and hygiene. More specifically, they opened administrative practices to a new and broader dimension of justification, such that urban hygiene and other matters could be justified and implemented as legally authorized practices of the state. This paper will address the legal and intellectual context in which these measures were fashioned and the rationale behind them, especially with respect to medical knowledge. Ultimately, the paper aims to demonstrate that two distinct processes worked concomitantly to create new powers of government in the process of early modern state-formation: the institutionalization of “public health” services and the usage of medical knowledge to implement and justify these services.