Parkinson's disease cannot be cured but symptoms can be improved by making use of physical therapy. The objective of the study was to compare the effect of routine exercises and Tai Chi on physical and clinical performance in elderly people suffering from Parkinson's disease. Data from interviews, physical and clinical performance, and levodopa consumption of 500 patients with confirmed Parkinson's disease (severity level I to III) were collected and analyzed. Participants who received 80 min/day Tai Chi 3 times/week for 2 months were included in the Tai Chi (TC) group (n=250) and those who received 90 min/day routine exercise 3 times/week for 2 months were included in routine exercise (RE) group (n=250). Timed up-and-go, 50-foot speed walk, and functional reach were improved by Tai Chi and routine exercise (P<0.05 for all) but intensities of Tai Chi for improvement of such parameters was higher than routine exercise. Incidence of falls was decreased by both physical therapies (P<0.05 for all) but more for the TC group (P<0.0001, q=38.512). In the TC group, at the end of follow-up, 22 (9%) patients were successful in withdrawal of levodopa treatment. Also, the dose of levodopa was decreased in patients of the TC group who had to continue levodopa. Tai Chi had the potential to slow down the progression of symptoms of Parkinson's disease and delayed the introduction of levodopa (level of evidence: III).