Clinical measures that Quantify falling risk factors are needed for the accurate evaluation of patients and to plan an intervention strategy. The purpose of this study was to examine the test-retest and interrater reliability of the dynamic gait index (DGI) for persons with Parkinson's disease (PD). A total of 22 idiopathic PD patients were recruited from rehabilitation hospital, Korea in this study. The DGI was assessed in two sessions that were, three days apart. We also measured Berg balance test (BBT) and geriatric depression scale (GDS) for concurrent validity with DGI. Intrarater and interrater reliability (.96 and .98 respectively) for DGI were high. indicating good agreement. The DGI was showed a good positive correlation with the BBS (r=.852). but not GDS (r=-.462). Intrarater and interrater reliability of DGI were high in people with PD. The DGI could be a reliable measure to evaluate functional postural control during gait activities in the PD population, and the ability of DGI to detect real change is acceptable in research and clinical settings.