Purpose: The aim of the present study was to investigate the effects of adapted exercise education on physical fitness levels of children with autism. Material and methods: The current study included eight autistic boys aged between 5 and 7 years. Subjects were divided into two groups. Group 1: Pool group (n=4): mean age 6.25 +/- 0.5 years, Group 2: Land group (n=4): mean age 6.0 +/- 1.15 years. Cardiovascular endurance, hand grip strength, speed and agility, flexibility and body composition of the subjects were recorded before and after exercise training. Exercise skills were applied by using one of the "errorless teachings methods" which is called the "most to least prompt" for during 40 minutes a day, three times a week for 12-weeks. Exercise program of land group was consisted of walking on treadmill, trampoline exercises, throwing the ball to the target, riding a toy horse and water group was consisted of water exercises and play skills. Results: At the end of the study when pre and post test evaluation results were compared significant differences were found in distance of the six minutes walking test, the amount of O-2 consumption (peak VO2), and percent (VO2%), running speed and agility, hand grip and sit and reach test (p<0.05) for both group. After training, there was no difference between the groups (p>0.05). Conclusion: The results of the current study showed that both exercise programs improved physical fitness of autistic children. It can be suggested that physiotherapists who are working with autistic children with communication and social integration limitations, may obtain useful results by the help of these kinds of adapted exercise programs and similar exercise programs.