Background: Parkinson's disease (PD) is a neurodegenerative disorder related mainly to the progressive loss of dopaminergic neurons in the substantia nigra pars compacta, a structure of the basal ganglia. Objective: To analyze quantitatively the changes in postural stability and static balance in patients with PD. Methods: The sample was comprised of participants with a clinical diagnosis of idiopathic PD, and healthy participants. The participants remained in static position on the force platform. Data were obtained with open and closed eyes. The following parameters related to the body, right foot and left foot were used as main variables: 1) Area of influence of the sway (COP-Center of Pressure), 2) Antero-posterior sway (AP COP), 3) Latero-lateral sway (LL COP), 4) Average speed sway (v) of COP AP and LL. Results: 34 volunteers underwent into two groups: (1) Parkinson Group (PG: 17 idiopathic PD-patients, age: 64.11±10.70), and Control Group (CG: 17 healthy controls, 60.47±8.53 years old). Without the visual feedback, PD-patients showed significant differences between healthy controls: COP of the body (p=0.004) and right foot(p=0.02); the sway of AP COP (p=0.009), right foot (p=0.03) and left foot (p=0.02) AP COP; vof the body AP COP (p=0.02), right foot (p=0.03) and left foot (p=0.01) v AP COP; sway of LL COP (p=0.01) and right foot (p=0.05) LL COP; v LL COP (p=0.01). Conclusion: The sway of center of pression in PD-patients showed worse when compared with healthy controls, wich may explain the greater probability to imbalances and falls in these people.