physical activity has been accepted as instrumental in the maintenance of functional ability and quality of life across the lifespan. despite the benefits of exercise, canada's physical activity guide to healthy active living (1999) reports that 60% of older adults are inactive. one of the outcomes of this inactivity is functional decline and consequent increased risk for falls. falling is one of the most common causes of injury and subsequent death in older adults. although the relationship between falls and functional decline is complex, several publications espouse that these risk factors can be modified through exercise (galindo-ciocon, ciocon, & galindo, 1995; lord, ward, williams, & strudwick, 1995). the purpose of the present study was to examine the effects of tai chi on biomechanical and functional measures of balance and gait in older adults who are at risk for falls. the participants in the study were 34 women with a mean age of 64 years, ranging in age from 55 to 85, who completed a 10 week program o f 8 forms of tai chi. all participants were assessed on forceplate measures of postural sway and measures of balance, gait, handgrip strength and falls, prior to and following the intervention period. tinetti's performance oriented mobility assessment (poma) was used to provide functional measures of balance and gait. postural sway variables that were examined included antero-posterior (ap) sway, area of sway, and path length and were measured during quiet standing with eyes open and eyes closed as well as during a dynamic balance space task. following intervention, completion of a social validation questionnaire provided a medium for expression of participant experiences. since 18 of the participants were novices with respect to tai chi and 16 had 34.44 hours of experience, the analyses were conducted by comparing the effect of the intervention on the two groups.