This essay focuses on the anti–malarial campaigns of Edmond and Etienne Sergent in colonial Algeria during the period from 1900 to 1930. This Pasteur Institute of Algeria was part of an elaborate, global network of men and institutions that constituted the scientific empire of Third Republic France. It was deeply indebted to the methods pioneered by Pasteur and to the shared foundational myth that connected the overseas Pasteur Institutes to Paris. But the Sergent brothers’ work operated within a dynamic context of international public health too. Algeria’s European settlers had also worked out a creolized identity that was both dependent upon and distinct from metropolitan practices. Ultimately, the Pasteur Institute of Algeria bore the mark of the settler colonialism that had given rise to it.