To evaluate the effectiveness of Tai Chi Chuan in fall prevention in elderly people living at home with a high risk of falling. Randomized controlled trial. Two industrial towns in the western part of the Netherlands. Two hundred sixty-nine elderly people (average age 77) living at home with a high risk of falling. The intervention group received Tai Chi Chuan training for 1 hour twice a week for 13 weeks; the control group received usual care. Both groups received a brochure containing general information on how to prevent fall incidents. Primary outcome was the number of falls over 12 months. Secondary outcomes were balance, fear of falling, blood pressure, heart rate at rest, forced expiratory volume during the first second, peak expiratory flow, physical activity, and functional status. After 12 months, no lower fall risk in the Tai Chi Chuan group was observed than in the control group (adjusted hazard ratio=1.16; 95% confidence interval=0.84-1.60), and there were no significant intervention effects on the secondary outcome measures. These results suggest that Tai Chi Chuan may not be effective in elderly people at a high risk of falling who live at home.