Thesis: This dissertation aims at opening the black box of African health progress during and following the colonial period. It does so by making three contributions to the literature on health policies, health standards and fertility patterns, in the 20th century’s Africa. The first chapter compares the colonial strategies for health policies’ provision and other colonial policies in former FrenchWest Africa between 1904 and 1958. Drawing on colonial archives and existing data, it gathers a unique dataset containing colonial inputs at the colonial district level: medical and educational staff, vaccinations, public work’s expenses and conscription. There was a very general strategy as regards to the provision of colonial services. In this context, the allocation of health inputs was specific in two dimensions only. First, medical staff was used as a means of colonial “coverage”. Second, there is a long-lasting effect of prevention leading to a “diversification” strategy for all health investments. Away from these specificities, the common factors to all investments have to do with the colonial administration’s preference for path dependence, investments’ returns to scale, the diseases’ contagion risk and the demand for colonial services. This work also suggests that there was no specialization of districts in one type of investments. The second chapter of this thesis looks at the relationship between adult height and underfive mortality in the context of the “double African Paradox” in West Africa. Africans are relatively tall in spite of extremely unfavorable income and disease environments. Moreover, their height stature decreased since the 1960’s despite improving health conditions and a fall in under-five mortality rates. This study points to selective mortality, by bringing forward a positive correlation between mothers’ height and mortality in the 1980’s West Africa. It then estimates a new model of height differential between survivors and deceased. Results imply that selective mortality could be large enough to mask significant height increases in the 1980’s West Africa. In high mortality contexts, anthropometric studies should discuss mortality levels and trends. More generally, results imply that the issue of selective mortality is crucial to assess the long-term impact of most health interventions. The third chapter tackles another specificity of African health: fertility and gender preferences. It develops a new indicator of gender preferences based on birth spacing. Applying it to Africa provides evidence that son preference is strong and increasing in North Africa, whereas Sub- Saharan African countries display a preference for variety or no preference at all. Traditional family systems accurately predict the nature of gender preferences, while religion does not. Last, the magnitude of preferences is stronger for wealthier and more educated women.