BACKGROUND(#br)Balance impairment is a major clinical concern in patients with parkinsonism. Balance training with tetra-ataxiometric posturography (Tetrax) is known to improve balance function through visual biofeedback effects.(#br)OBJECTIVE(#br)In this study, we evaluated the effects of balance training with Tetrax in patients with parkinsonism.(#br)METHODS(#br)Patients with parkinsonism (idiopathic Parkinson’s disease, multiple systemic atrophy, and multiple systemic atrophy) who were able to stand with or without an assistive device were recruited for the study. Twenty patients with parkinsonism were randomly assigned to one of the following two groups: (1) the Tetrax group, in which patients received Tetrax biofeedback balance training for 30 min/day for 2 weeks (10 sessions); and (2) the control group, in which patients received conventional balance training for 30 min/day for 2 weeks (10 sessions). One day before and after training, we measured patients’ balance parameters using the Berg balance scale (BBS) and fall index (FI).(#br)RESULTS(#br)The BBS and FI scores of the Tetrax group showed significant improvements after compared to before training. However, the scores in the control group were not significantly changed after vs. before conventional balance training.(#br)CONCLUSIONS(#br)For patients with parkinsonism, Tetrax biofeedback balance training had a positive effect on balance function