Introduction: Motor skills play a crucial role in children's learning and everyday skills. Therefore, any disorder in children’s motor skills may result in having weakness and facing difficulty in educational, social and other skills. The aim of this study was to compare motor skills of children with mental retardation as opposed to normal children by taking into account the factor of mental age, so as to conduct, using the results, a more accurate assessment and treatment in this regard.
Methodology: In the present study, 15 normal children and 15 children with mental retardation were selected using convenient convenient targeted sampling. To this end, we used Lincoln-Kerensky motor development scale. To compare the two groups, we took advantage of the independent t-test using software and significance levels
Results: The results indicated that there is no significant difference between hand/foot coordination of normal children and mentally retarded ones; nevertheless, such a difference did exist regarding body balance skills of throwing, grabbing and jumping between children in the normal group and those in the mentally retarded group.
Discussion: The results showed that the mere compensation for the time delay of mentally retarded children is not adequate for addressing the delay in their motor skills. Hence, in order to naturalize motor skills of children with mental retardation compared with their normal peers, it is necessary to design and implement targeted educational-therapeutic programs for these children in occupational therapy centers.

Key words: motor skills, mental age, Lincoln-Oseretsky Test