Brua is an Afro-Caribbean religion and healing tradition predominantly practised on the ABC islands of the former Netherlands Antilles. It is grounded in oral tradition and shrouded in strict social taboos. Existing literature suggests that the majority of people on and from the islands are familiar with Brua and that it plays a substantial role in shaping their illness conception and idioms of distress. A lack of knowledge of Brua may therefore lead biomedically trained health professionals to misdiagnose these patients. This article discusses how religious beliefs related to Brua influence the illness concepts and idioms of distress of psychiatric patients originating from the ABC Islands, based on semi-structured interviews with former islanders receiving treatment at a psychiatric institute in the Netherlands. We found that of the 29 interviewees, 93.1% knew what Brua involved, 72.4% believed in it, 48.2% had first-hand experience with Brua practices, and 34.5% attributed their mental illness to Brua with greater or lesser certainty. However, only one patient had previously discussed her belief in Brua with her psychiatrist and only when asked to do so. The role of psychoactive substances in the context of Brua practices was negligible. Thus, the present study indicates that the majority of psychiatric patients from the ABC islands are familiar with Brua, but feel reluctant to discuss their concerns in this area with mental health professionals. Recommendations for clinical practice and further research are provided, including the need for a culture-sensitive approach and integrative care.