Across the European empires, evangelisation and education were perceived as part of a broader process of human transformation aimed at reordering societies and reshaping worldviews. After the Second World War, international debates on the education of colonised peoples, linked to human development and race, embodying the perceived secularised and leftist ideals of international organisations (such as the UN and Unesco), alarmed Catholic sectors in the colonial context. Would UNESCO's educational projects benefit the Catholic mission or challenge it? Many Catholics suspected these external considerations on colonial issues and questioned its internationalist aims. Focusing on the Portuguese case, this presentation explores the Catholic attitudes regarding UNESCO's attempts to collaborate with the empires in colonial education in Africa in the 1950s, relating it to the debates on the continuation of the imperial system, the transformations within the Catholic Church and the role played by the missionaries in colonised societies.