Data on the nature of the problems of the mentally retarded in the juvenile justice system were derived from court social histories and interviews with court personnel. Retarded youth were found to comprise 7 percent of the sample of scored cases (retarded youth were identified as having I.Q. scores of 70 or below). The court does not have a standard procedure for identifying retarded youths and determining their special problems or needs. Retarded youth are generally younger than the borderline and the nonretarded, and males dominate the retarded group. Prior court history and types of complaints are similar for all groups. The court staff is not trained to work with retarded youth who have behavioral and learning problems. Ohio Youth Commission placements constitute 25 percent of the dispositions for the retarded, with withdrawals or dismissals being 22 percent. Residential placements for the retarded are in short supply, and more than half of the below-80 I.Q. group are not enrolled in special education classes. Information on personal adjustment variables often is not available in the records, and service plans are not routinely recorded in the social histories. A reliable assessment procedure should be the first step in developing and improving services for the mentally retarded juvenile offender. To serve such youth more efficiently, intake workers, probation officers, judges, public defenders, and detention staff require training on mental retardation. There should also be a mental retardation resource person in juvenile court who identifies, develops, and coordinates community resources for the mentally retarded offender. Finally, a range of community residential services should be developed for such offenders. Tabular data, 15 notes, and 12 references are provided.