The purpose of this article is to present a model to promote and assess interculturalization of mental healthcare services in western multicultural society. We define interculturalization as the adaptation of mental health services to suit clients from different cultures. The suggested measures aim to introduce changes in four contexts: (i) the clinical interface or the relations between the immigrant patient and the healthcare workers and the treatment team; (ii) organizational adaptations required in the treatment context of the mental healthcare facility; (iii) the relation between the mental health facility and the ethnic communities; and (iv) the relation between the mental healthcare system, other facilities and society at large. To monitor the desired changes, the model describes qualitative and quantitative criteria and indicators to be applied in the four contexts.