Objective: To evaluate the effect of the Ai-Chi method on the functional activities, quality of life, and posture in patients with Parkinson disease. Methods: The sample was divided into 2 groups: intervention (Ai-Chi method exercises; n = 8) and control group (without exercises; n = 7). Subjects were assessed for functional activities (Unifi ed Parkinson's Disease Rating Scale), quality of life (39-item Parkinson's Disease Questionnaire), and posture (postural assessment software SAPO). Results: The subjects in the intervention group showed improvement in functional activities (Unifi ed Parkinson's Disease Rating Scale score, 38.3 vs 23.8, P = .02) and posture (21.53 vs 21.86, P = .029). Conclusion: The Ai-Chi method improves functional activities and head posture in patients with Parkinson disease.Regarding aquatic exercises, there are already scientifi c reports about the effects of these exercises on subjects with PD; however, there is still a need for controlled and systematic studies, covering in detail the criteria for inclusion and exclusion, the disease level, along with the description of the technique used because currently these are scarce. 5 Ai-Chi is a technique used in aquatic physiotherapy in a heated pool with the goal to improve mobility, meditation, relaxation, and body stretching where movements are performed slowly and continuously. 6 These movements performed in a systematic way can infl uence the daily life activities of patients with PD since the changes resulting from the disease affect posture, locomotion, and quality of life (QOL) aspects. However, there are no studies to date in the literature demonstrating the effects of this method on clinical and functional outcomes in PD.Therefore, the aim of the study was to analyze the effects of Ai-Chi on functional activities, QOL, and the posture of patients with PD.