This article presents the results of two evaluation studies of the intercultural mediation program in Belgian health care. From the first study it became clear that the program led to an important increase in the quality of care if adequate use was made of the intercultural mediators’ services. In the second, many factors were found to hamper its efficiency and effectiveness. These were related to a lack of skills and knowledge, as well as certain attitudes, in health care providers and intercultural mediators. The results of both studies led to the development and implementation of a quality assurance and improvement program that should increase the efficiency, effectiveness and quality of the work of the intercultural mediators. This program is briefly described and its impact is discussed.