This paper investigates British colonial policies and attitudes towards Cairo’s slums and “native quarters” (neighborhoods where mostly Egyptians lived) against the broader background of how the city became an object of colonial governance during the formative years of the British occupation of Egypt (1882-1922). Exclusionary geography was indeed crucial to colonial urban policies and to colonial visions of how to command the city and its future. It was anchored in a particular understanding of the place of the city in what colonial officials believed to be a country of peasants, and in a conception of rule that sought to direct the circulation of people and the processes of life along well-monitored channels. One year into the British occupation of Egypt, British officials faced many challenges, from the reorganization of Egyptian finances to establishing order in the countryside and the south. However, another stern challenge to British rule came from an unlikely source, a biological agent, namely cholera. The disease swept through the country during the summer of 1883 claiming thousands of lives and an estimated 8000 in Cairo alone, mostly within three disastrous weeks. This paper will examine the colonial governance of Cairo’s slums by focusing primarily on British public health policies. Such policies reveal how the British saw the city in Egypt, especially as a sociological anomaly. They also reveal how British officials, armed by late-Victorian confidence, utilized science and technology to solve problems of rule. Finally, they underscore the formation of an unstudied colonial discourse on slums as sites of biological and social danger, a discourse that was later appropriated by nationalist elites at a moment when the role of governments in matters of health and urban planning became part of the political vocabulary available for both proponents and critics of British colonial rule. The bulk of the paper will focus on cholera epidemics and sanitation in Boulaq and Misr al Qadima—areas where slums continue to exist to this very day—examining the work of various sanitary commissions and urban engineering reports with an eye on the place of slums in colonial urban planning. It will briefly look at drugs, their sale, and circulation within Egyptian neighborhoods. Finally, focusing on the work of public hygienists and sanitary engineers, the paper will trace how the slums became the object of expert analysis and quasi-anthropological investigation.