Decrease of Dual-Task (DT) ability is known to be one of fall-risk factors. We developed a new game concept, Dual-Task Tai Chi (DTTC), using Kinect (Microsoft Co.), a motion-capture device, and demonstrated that the DTTC test can quantitatively evaluate various functions that are known risk factors for falling in elderly adults. Moreover, DT training has been attracting attention as a way to improve balance and DT ability. However, only a few studies have reported that it improves cognitive performance. Therefore, the purpose of this study was to demonstrate whether or not a 12-week program of DTTC training would effectively improve cognitive functions. A total of 41 elderly individuals (training group: n = 26, control group: n = 15) participated in this study and their cognitive functions were assessed before and after DTTC training. Significant differences were observed between the two groups with significant group × time interactions for the executive cognitive function measure: Δ trail-making test (part B-part A) (p < 0.05). The results suggest that DTTC training is effective for improving executive cognitive functions. © 2013 ICST.