The paper traces developments over the last 30 years in Scandinavia regarding the treatment of individuals with mental retardation. Noted are shifts toward decentralization and integration, with the most radical changes taking place in Denmark. The critical role of voluntary organizations in Denmark, Norway, and Sweden is observed. Operation of service delivery systems is illustrated through a case study of one Norway region's approaches to serving its mentally retarded population. Folk High Schools, designed to ease the transition from adolescence to adulthood, toy libraries, and therapeutic communities in which mentally retarded and nonretarded persons live and work, are three Scandinavian contributions to the field. Cross-national cooperation is evident in many areas related to the handicapped. Among matters of concern cited are generally inadequate employment, lack of personnel, and tightened budgets for social services. (CL)