From the late nineteenth until the mid-twentieth century, colonial actors conceived and tried to implement a wide array of interventions aiming to improve the ‘quantity and quality’ of the ‘native’ population in Angola. These population politics were inextricably linked to the pervasive idea of a demographic crisis: virtually all colonial actors assumed that the ‘native’ population was declining or at best stagnating, and suffering from ill-health. The emergence of these depopulation anxieties was intimately connected with a major epidemic of sleeping sickness in the 1890s and the changing political, economic and ideological imperatives of colonial rule in what had been a Portuguese colony for many centuries. These new imperatives emphasised the importance of a healthy and growing ‘native’ population for the success and legitimacy of modern colonial rule, and the importance of Angola for the future of the Portuguese nation. The ideal of a growing and healthy population was firmly linked to the changing labour demands of the colonial economy: depopulation scares usually intensified in phases of economic expansion, as in the 1890s, 1920s, or during and directly after the Second World War, when they dovetailed with fears of labour scarcity. Depopulation anxieties persisted until the late 1940s, but over the decades, primary explanations gradually shifted from excessive mortality caused by epidemic and endemic diseases to low birth rates, high infant mortality and rampant emigration.