From the years 2000s, training and research programmes in disaster risk reduction have developed throughout the African continent, and most particularly under the aegis of South African scientists. These programmes aim to develop a sound and expert approach to disaster management, that would support the management and the prevention of disaters by African states through the professionalisation of local expertise. This development of expert knowledge may at first sight appear as a by-product of global governance as it is heavily funded by USAID and participates to a global movement, led by the UN, that seeks to promote models of risk management in order to prevent disasters and ensure stability. Although it is necessary to acknowledge these global macro factors, this paper will seek to develop alternative explanations to the development of this science, its role and its effects. By adopting a fine grain analysis, following scientific trajectories, analysing carefully circulations of knowledge and experts, I will show that disaster science is not a simple intermediary between international organisations and the local environment, but also serves as a producer of knowledge both in Africa and globally. To do so, I will trace the development of a disaster science in South Africa and its ramifications on the African continent, at the crossroads of international development, state transformations, and academic practices. More generally, using insights from political sociology of science and historical studies of colonial science, this paper aims to contribute to the analysis of contemporary dynamics of expertise and science in Africa.< Réduire