Mental deficiency is not a disease in its own right but a condition resulting from a variety of causes, some inborn and others acquired. The skin abnormalities of mental defectives fall into three broad groups: 1. Cutaneous lesions specifically associated with syndromes of genetic or developmental origin. 2. Non-specific cutaneous lesions showing an increased prevalence in mental defectives. 3. non-specific cutaneous lesions.

We examined 110 mental retarded cases in Fayyaz Bakhsh center during 7 months from April to November 1994. Their skin disease were diagnosed by physical exam. Smear, biopsy  and pathology.

Most cases were predominantly children and skin disease in 5-15 years age group was more than the other group.

In patients with IQ < 25 , the incidence of skin disease was more than the others.

Also the incidence of skin disease in mental retarded with anomaly was higher than the other groups.

The infectious skin disease in severe mental retarded was high. Most of skin disease were in second and third group.

The results of statistical comparison showed that impetigo was the most common skin disease in this study.