Psychiatric patients of non-western origin leave treatment against the advice of their clinicians far more often than do their western counterparts. This article presents a theoretical framework for better understanding such clinical cases, developed from examples of psychiatric practice in different cultures. The theory is based on two meanings of the concept of culture, an elaboration of the universality-relativity dichotomy, and a view of the work of mental health care providers as involving three components: (1) building a trusting relationship with the patient; (2) making a diagnosis and treatment plan; and (3) carrying out treatment that is acceptable and meaningful to the patient. The article argues that all psychiatry is transcultural psychiatry, because a cultural gap always exists between the psychiatrist and the patient.