The increasing expansion and intensity of European imperialism overseas produced new knowledge on purity, health and cleanliness, which affected the development of hygiene. This chapter begins by exploring the Basel Mission’s activities on the Gold Coast since 1828 and in Cameroon since 1885, which included far-reaching economic, social and medical policies. The involvement of the Basel Mission in delivering health care to the population in West Africa was increasingly valued by imperial policy-makers. There was a marked shift between 1885 and 1914 from an initial emphasis on the health and survival of white colonists to the teaching of hygiene to the resident population in the colonies, ostensibly for their own benefit. The improvement of “indigenous hygiene”—as it was referred to during the colonial period before World War I—became a key concern of colonial governments in Africa around 1900, for both economic and cultural reasons. The tropics provided a setting in which the Basel Mission doctors not only gained scientific reputation but also political authority.