Tuberculosis, once a leading cause of death in Europe and North America, was understood to be preventable and even curable by the early twentieth century. Yet despite growing knowledge about the disease and interventions that would slow its spread, tuberculosis deaths among First Nations in Canada remained staggeringly high. Government policies rooted in colonialism exacerbated a tuberculosis epidemic. Wilful Neglect explores the devastating consequences of the Department of Indian Affairs’ failed responses to tuberculosis among First Nations in Canada from 1867 to 1945. Even when medical treatment for tuberculosis became widely available, and despite the federal government’s obligations being written into treaties and other legislation, the basic health needs of First Nations remained unmet. The government instead prioritized an assimilationist agenda, including the placement of Indigenous children in residential schools, which became hotbeds for the spread of the infection. Drawing on the department’s own annual reports, memoranda, and budgets over more than seventy years, Jane Thomas traces key moments, decisions, and individuals involved in shaping federal health policy, laying bare the consequences of racializing a disease. Health policies developed by colonial governments without the involvement of First Nations have always failed. Wilful Neglect demonstrates a direct link between the federal government’s historic health policies and the disparities that continue into the present.