In this study we demonstrate that hydrotherapy can in crease muscle strength (Figure1), peak expiratory flow ( figure2) and RML (figure 3) in individuals with Down syndrome. The importance of this finding is due to the that respiratory muscle weakness contributes to the onset of respiratory disease in these individuals 4. Regarding the profile of the sample, we found that most individuals met the BMI values above the normal rang, confirming the findings in the literature for this population 4. However, although obessity be considered a risk factor for respiratory disorders9-10, hydrotherapy treatment did not exert influence on this characteristic. In dynamic cirtometry auxiliary and xiphoid nipple values were lower than expected, showing a decrease in thoracic mobility in these individuals. This can be explained by the high occurrence of hypotony for individuals with Down syndrome, who at birth, can reach about 93.0% of cases. Thus, it is necessary to the application of therapies that aim to improve the dynamic optimzing circumferences, so the mobility of the chest. Noting the findings of respiratory muscle strength one finds that depicts the sample values well below the limit for MIP and MEP for both pre, 34,9% and 46,5% of predicted, and after treatment, 53,2% and 53,8%, respectively, showing alterations in the integrity of the respiratory muscles. We therefore reaffirm the importance of application of therapy to in crease muscle strength of these individuals.