The purpose of this study was to assess the effect of T' ai Chi Chuan training on lateral stability, kinesthetic sense, and strength of voluntary knee extension. Subjects consisted of 24 naive volunteers (12 men and 12 women) between the ages of 20 and 45 years. Pre- and 12-week posttests included lateral body stability, kinesthetic sense in the glenohumeral joint for 30 degrees, 45 degrees, and 60 degrees, and strength of knee extension. After pretest data collection, 12 subjects performed T'ai Chi Chuan three times per week for 12 weeks, learning 108 forms of T'ai Chi Chuan. A 2 x 2 analysis of variance was used to estimate significance of group differences on all of the dependent variables. Significant group differences were found in lateral body stability, kinesthetic sense at 60 degrees, and strength of the dominant knee extensor. No significant differences between the T'ai Chi and the control group were found for kinesthetic sense at 30 degrees and 45 degrees rotation of the glenohumeral joint. Film analysis indicated that the two lesser angles were not as common in the T'ai Chi training as the greater angle (60 degrees) and thus may be less practiced. It appears that T'ai Chi Chuan presents a low-stress method to enhance stability, selected kinesthetic sense, and strength of knee extension.