This thesis describes the major intercultural challenges encountered by health professionals working with diverse patient populations and their impact on clinical care, and discusses cultural competence as a strategy to improve care to these patients. The situation at the Geneva University Hospitals (HUG), as a case example of institutional responses to cultural diversity, is portrayed, including the activity of the HUG's Cultural consultation. The thesis concludes by expanding the notion of cultural competence to other vulnerable groups and drafts future perspectives for research, training and clinical work.