This prize-winning study examines the nightmarish effects of the so-called “wonder drug” in preventing sleeping sickness in Africa. After the Second World War, French colonial health services set out to eradicate sleeping sickness in Africa. The newly discovered drug Lomidine (also known as Pentamidine) promised to protect against infection, and mass campaigns of “preventive lomidinization” were launched across Africa. But the drug proved to be both inefficient and dangerous. In numerous cases, it led to fatality. In The Lomidine Files, Guillaume Lachenal traces the medicine’s trajectory from experimental trials during the Second World War to its abandonment in the late 1950s. He explores colonial doctors’ dangerous obsession with an Africa freed from disease and describes the terrible reactions caused by the drug, the resulting panic of colonial authorities, and the decades-long cover-up that followed. A fascinating material history that touches on the drug’s manufacture and distribution, as well as the tragedies that followed in its path, The Lomidine Files resurrects a nearly forgotten scandal. Ultimately, it illuminates public health not only as a showcase of colonial humanism and a tool of control but also as an arena of mediocrity, powerlessness, and stupidity. Winner of the George Rosen Prize by the American Association for the History of Medicine