The development of a boy who at age six was diagnosed as having "an emotional form of retardation" and "psychosis" is reported and followed to adulthood. Initially untestable for IQ, he ultimately tested stably low in the mildly retarded range. At referral he showed severe deficiencies in ego development. He improved following several years of psychotherapy and concurrent casework with the parents. At age twenty-seven he was still mildly retarded, but self-supporting and free of significant personality disabilities. This presentation both exemplifies the usefulness of psychotherapy and family casework in the treatment of a retarded child, and strongly supports the growing reinvestment in mental retardation by psychiatry and child psychiatry.