In comparison with the community mental health care services, the residential und semimural mental health care sector in the Netherlands has hardly given serious attention to the process of multiculturalization of the population. To improve the services for immmigrants a number of measures is proposed. These measures modify four different treatment contexts: (a) the relation between the immigrant patient, therapist and treatment team; (b) the treatment context in the institution; (c) the relation between the hospital and the ethnic group; (d) the relation between the mental health care system and the society. In addition, the paper provides a methodology for quality surveillance of the process of change within each of these four contexts. A number of qualitative and quantitative criteria and indicators to monitor the process of multiculturalization of mental health services are mentioned.