The purpose of this study was to define if active participation of Greek adults with mental retardation (training) in programs of exercise, would contribute to the development of their physical fitness, of the gross and fine neuromuscular coordination and of their reaction time. The sample of the study was 65 people (21 girls, 44 boys) who made three groups A, B, C, with the size of 23,22 and 20 people correspondingly. The members of group A, were people of mental retardation with an I.Q. varying from 38 to 54, (M=42.75 & SD=5.85) in Havie test. Their chronological ages ranged from 16.1 to 30.2 years (M= ). The other two groups with normal intelligence were used as control groups. The members of group Β had chronological age from 15.1 to 28.0 years (M=). The members of group C, had chronological age from 6.1 to 9.0 (M=).People from group A had the same chronological age with people from group B, while they had the same mental age with group C. Initially all three groups were submitted to a test of physical fitness, neuromuscular co-ordination, fine motor co-ordination and reaction time.People with mental retardation, were submitted to the same tests twice more : a), after their seven month-everyday participation to the program of exercise and b).after their three month abstinence from the program of exercise.The testing of the results was done by the use of MANOVA-repeated measures and ONE-WAY analysis.The results of the analysis showed that the group of people with mental retardation achieved important:1. improvement regarding to the elements of physical fitness, except of the strength of the legs where appeared a tense of improvement.2. improvement in its record to the test of neuromuscular coordination 3. improvement in the tapping of the left hand, while the records of the right hand had only a little improvement. Moreover the exercise significantly improved the records of the group in long pins while there weren't any changes in aiming.4. reduction only in the reaction time which was examined to light stimuli-reaction by hand, while also important was the improvement that was made in the number of right delayed and lost answers in all stimuli to fine and gross motor movements. VII 5. performed much worse than people with the same age of normal intelligence in all tests and measures. 6. significantly excelled in sit ups and strength of hands than children of normal intelligence while it was far behind in flexibility, in short pins and at time of aiming completion.So, in conclusion, the participation of people with mental retardation in exercise programs ensures the advancement of their physical fitness and improve their fine eye-motor coordination and their reaction time.