This article presents the result of research on the perceptions about the meanings, causes, symptoms and treatments of mental disorders in contemporary Timorese society. To this end, semi-structured interviews were conducted with 48 matan-dook – healers, doctors and mediators between the world of the living and the world of the dead by ancestral customs and practices – in the municipalities of Aileu, Ainaro, Dili, Liquiçá, Los Palos, Maliana, Manatuto, Manufahi and Viqueque. In general terms, mental disorders would have a somatic-psychic-spiritual character and would be the consequence of actions perceived as deviant from the socially established norm, constituting a rupture in the conception of harmony and social order.