1911 to 1935 was a chaotic, yet foundational, period in the transformation of the police force in Tehran and Iran more broadly. The nationalization of modern Iranian policing can be traced back to this time period. This article explores the role of nationalism and anti-imperialism on policing, how the structure and process of policing underwent transformation, including how police were recruited, trained, and deployed. Localized and decentralized policing was slowly abandoned in favor of an integrated national force, with policing through mediation being replaced with the exercise of power in a top-down and center to periphery manner. Education of police officers also underwent transformation, as new strategies were pursued to create a modern nationalist Iranian police force.