This article describes the establishment of psychiatry in Italy’s former colonies during the period 1906–43, in terms of the clinical and institutional mechanisms, the underlying theories and the main individuals involved. ‘Colonial psychiatry’ (variously called ‘ethnographic’, ‘comparative’ or ‘racial’ psychiatry) – the object of which was both to care for mentally afflicted colonists and local people and also to understand and make sense of their pathologies – received most attention in colonial Libya, starting in the first months of the Italian occupation (1911–12) and then taking institutional form in the 1930s; in the colonies of what was known as ‘Italian East Africa’, on the other hand, less was said about psychiatric care, and practical achievements were correspondingly limited.