The recent focus on the history of knowledge has traced the circulation of scientific objects and discourses across temporal and geographic boundaries. In light of these explorations, the role of migrants as key facilitators of circulatory regimes, provides exciting avenues of study. Linking the history of knowledge with the history of migration, this paper will focus on “knowledge-migrants,” a heterogeneous group of Muslim scientists and their technical training at German universities, who were responsible for the development of postcolonial scientistic institutions in Afghanistan. As a case study, the paper presents the work of ‘Abd al-Rahim Khan (b.1909), a German-educated migrant-turned-physician who trained in bacteriology at the Hygiene Institute of the Friedrich-Wilhelms-Universität of Berlin. While we know of European scientists and their research agendas in the Middle East, what we do not know is how German scientific institutions in the interwar period became key spaces for Muslim scientists to develop innovative scientific techniques, such as new ways of propagating and and observing bacterial changes over time – a key skill that Rahim Khan drew on when examining malaria swamps across Afghanistan and India. Reading his 1939 work for the ways in which it problematized Robert Koch’s preferred medium of agar to grow and control bacteria, the paper also links his early formative years in Berlin to the development of the first medical centers across Afghanistan. In decentering the methodological and conceptual narrative of migrants as passive observers of their new societies, this paper highlights not only the role of Muslim migrants in shaping the histories of German sciences but also their work in translating science across intercultural terrains.