The purpose of the study was to determine the effects of Pilates on the health-related physical fitness of individuals with disabilities. The health-related components included aerobic functioning, body composition, and musculosketal functioning (flexibility, muscular strength, and muscular endurance). The participants were 21 boys and 10 girls, aged 10-17 years (M=13.45±2.29), who had been diagnosed with mild to moderate cognitive disabilities. Some individuals had other disabilities that included autism, cerbral palsy, and down syndrome, and traumatic brain injury, visual or auditory impairment. All individuals were students in an adapted physical education program in a Midwest school district. This study was approved by the Instuctional Review Board of Southern Illinois University Edwardsville and all students had parental/guardian permission to participate. All students paricipated in fitness test items appropriate for their age and disability. These tests were selected from the battery included in the Brockport Physical Fitness Test. Pre and post-tests were conducted within a two week period prior to and immdediately following the Pilates intervention. The intervention included twenty-four, 30 min, Pilates beginner mat sessions, conducted by a certified Pilates instructor. Dependent t-tests were used to analyze the pre and post-test scores, with the p value set at £.003, using the Bonferroni method to control for Type 1 error. The results of the study showed that Pilates had a significant effect on the musculoskeletal functioning components of pre (M=24.74±1.64 cm) and post (M=27.45±1.02 cm) trunk lift (p=.001), pre (M=3.37±5.69 sec) and post (M=6.67±7.05 sec) flexed arm hang (p=.002), and pre (M=20.84±14.89 reps) and post (M=40.45±22.56 reps) curl-ups (p=.000). There was an increase in pre to post-test mean scores in all testing areas, except the back saver sit and reach, right side, where a decrease of .18 cm was found. The conclusion of this study was that the Pilates beginners mat workout may have an impact on health-related fitness, especially in the areas of abdominal strength, trunk extension, and upper body strength and may have produced a slight increase in the other areas of physical fitness. Although Pilates is not a new form of exercise, there is very limited research and more studies are needed utilizing Pilates as an intervention. Keyword(s): adapted physical activity, exercise/fitness, physical activity