OBJECTIVES: To determine whether an intense tai chi (TC) exercise program could reduce the risk of falls more than a wellness education (WE) program in older adults meeting criteria for transitioning to frailty. DESIGN: Randomized, controlled trial of 48 weeks duration. SETTING: Twenty congregate living facilities in the greater Atlanta area. PARTICIPANTS: Sample of 291 women and 20 men aged 70 to 97. MEASUREMENTS: Demographics, time to first fall and all subsequent falls, functional measures, Sickness Impact Profile, Centers for Epidemiologic Studies-Depression Scale, Activities-specific Balance Confidence Scale, Falls Efficacy Scales, and adherence to interventions. RESULTS: The risk ratio (RR) of falling was not statistically different in the TC group and the WE group (RR = 0.75, 95% confidence interval (CI) = 0.52-1.08), P =.13). Over the 48 weeks of intervention, 46% (n = 132) of the participants did not fall; the percentage of participants that fell at least once was 47.6% for the TC group and 60.3% for the WE group. CONCLUSION: TC did not reduce the RR of falling in transitionally frail, older adults, but the direction of effect observed in this study, together with positive findings seen previously in more-robust older adults, suggests that TC may be clinically important and should be evaluated further in this high-risk population.