This study sought to investigate the effect of family characteristics on placement of learners with mental retardation. A case study of Moyale School for the Mentally Retarded in Moyale County was taken. The study was guided by the following objectives; To identify the profile of respondents in terms of age, gender,marital status and work experience, to determine family characteristics of learners with mental retardation, to determine levels of mental retardation in institutions and to determine if there is a significant relationship betwen family characteristics and placement of learners in institutions, The study found out that most learmers in institutions come from poor families, it also found out that there is a significant relationship between family characteristics and placement of learners with mentally retarded children, It was recommended that in order to deal with learners with ental retrardation, poverty alleviation programmes should be initiated at grassroots so that family characteristics are altered.