This article analyzes the process of reforming police practices and institutions in Tunis during the period of the Tanzimat. Working from the unpublished annals of the sheikh al-madîna, the head of the pre-Tanzimat municipal institutions, and from archives pertaining to the creation of new police forces during the reforms, it engages with a series of ongoing debates in historiography about the nature of modernization processes in a province of the Ottoman Empire that was already subject to European colonialist pressures and about the relationship between the imperial structure, local notables and the urban population. The main argument illustrates how modernization was a complex process of continuity and change in which the negotiation of new institutional, bureaucratic, and social features was a central issue. Reevaluating the importance and character of pre-Tanzimat institutions also suggests that we read the process that led to modernization and the nature of modernity itself with a critical lens.