A proposal for deinstitutionalization of the mentally retarded in Norway passed the Norwegian Storting in May 1988. The Ministry of Health and Social Affairs has prepared guidelines for planning and implenting this reform. On 1 January 1991 the responsibility for providing the necessary services was transferred to the municipalities. Many problems have to be solved in order to ensure that the life of each mentally retarded person is qualitatively improved after normalization and integration into society. In July 1989 the Ministry of Health and Social Affairs issued a document which assumed that necessary specialists and special services for the mentally retarded already exist, and are being used. Our study has questioned this assumption as being incorrect or incomplete. We interviewed persons in charge of the system of health care in all 19 Norwegian counties. Our conclusions are as follows: The mentally retarded do receive specialist services in various areas of somatic medicine. Their needs as regards psychiatric care are not taken care of by psychiatric specialists in hospitals or at out-patient facilities. Data shows that the system of institutionalized health care for the mentally retarded provides unique services which are best described as systematically applied behaviour analyses. Such special competence is often lacking in the Norwegian health services otherwise. In order to ensure that the mentally retarded will receive the best possible care, this competence must be integrated into the future system of care. It is most importance to consider these problems without delay. This article also discusses organizing special training and treatment for the mentally retarded themselves and special training for the persons providing the care.