Background: balance control is a major problem for older individuals with poor vision. There are limitations, however, for visually impaired elderly persons wishing to participate in exercise programmes. The benefits of Tai Chi for balance control, muscle strength and preventing falls have been demonstrated with sighted elderly subjects. This study was designed to extend those findings to elderly persons with visual impairment.Objective: to investigate the effects of Tai Chi on the balance control of elderly persons with visual impairment.Design: randomised clinical trial.Setting: residential care homes.Subjects: forty visually impaired persons aged 70 or over.Methods: the participants were randomly divided into Tai Chi and control groups and assessed pre- and post-intervention using three tests: (i) passive knee joint repositioning to test knee proprioception; (ii) concentric isokinetic strength of the knee extensors and flexors and (iii) a sensory organisation test to quantify an individual's ability to maintain balance in a variety of complex sensory conditions.Results: after intervention, the Tai Chi participants showed significant improvements in knee proprioception and in their visual and vestibular ratios compared with the control group.Conclusion: practicing Tai Chi can improve the balance control of visually impaired elderly persons. ; Department of Rehabilitation Sciences