Mental retardation was not only a problem of intellectual deficit but also it had its impact on the perception of self-image. This study was done to assess the perception of mildly mentally retarded children of their external bodies. Also, its aim was to design some play techniques and to test their impact on developing the perception of mildly mentally retarded children of their external body parts. The study was conducted in El Tarbieh El Fekrya School in Shebin El Kom. The sample included 25 mentally retarded children with IQ level between 50 and 68 in preparatory A & B. The hypothesis of the study was that play could stimulate the interest of mentally retarded children in learning about their external body parts. The play techniques included games such as put your body part inside a circle, ball throwing, jumping, walking on tiptoes, picking objects from the floor, holding the candy with your fingers, who can open his mouth, putting the candy in your friend's mouth, putting the necktie around any neck and mirror play. The results of the study showed the effectiveness of the designed play interventions on developing the perception of mildly mentally retarded children about their external bodies. It was concluded that properly designed play interventions could help mildly retarded children to acquire appropriate perception of their external bodies.