Introduction: There are a few researches about effects of exercises on physical fitness factors of children with mental retardation. The aim of the present study was to review the effect of eight weeks of posture and balance training on physical fitness factors of children with mental retardation.

Methods: Thirty voluntary students of Laleh Mental Retardation Elementary School of Yasuij city were selected as the sample by purposive sampling. In the pretest stage, all subjects were measured with a static balance, dynamic balance, muscle strength, flexibility and muscle endurance, and were then divided to two groups of experimental and control. The experimental group was trained with selective exercises for eight weeks and the control group performed their daily activities. After eight weeks, in posttest, all variables were measured again in the same manner as the pre-test stage.

Results: Results showed that eight weeks of posture and balance training had a significant effect on improvement of static balance (P = 0.02), flexibility (P = 0.001) and muscle endurance (P = 0.006) of children with mental retardation; nevertheless, it had no significant effect on improvement of dynamic balance (P = 0.99) and muscle strength (P = 0.11) of children with mental retardation.

Conclusions: Regarding the findings of the present research, it is concluded that to improve the physical fitness of children with mental retardation, eight weeks of posture and balance training could be used.