Written primarily for social workers who deal with the retarded and their families, the text surveys the needs in mental retardation and ways of meeting those needs. Aspects considered are causes and manifestations, evaluation and planning, and organizational problems; the retardate in the community; behavioral manifestations; and social implications. Services are discussed in terms of the process of discovery and information, special services, special use of community services, residential facilities, and services to the family; social work goals and techniques are described along with situational problems. Services to the retarded and their families are treated with reference to the social workers on the professional team, the psychosocial diagnosis, the professional relationship, and casework treatment. Also presented are some specific concerns of parents and social workers in looking ahead and conclusions regarding social work research and consultation in the future. (JD)