Background and Purpose. To describe the effects of an eight-week Tai Chi class on two patients: one with Parkinson's disease, the other with multiple system atrophy. Method and Results. Both patients demonstrated improved scores on the Activities-specific Balance Confidence Scale and the Functional Reach Test. One subject also demonstrated improved scores for the Timed Up and Go test. Both subjects reported subjective improvements in balance and balance awareness. Conclusions. Tai Chi may be a viable option for improving balance in patients with mild Parkinsonism. Copyright © 2005 Whurr Publishers Ltd.