Tai chi exercise has been recommended as suitable for the improvement of health in the elderly. The purpose of this study was to investigate the effects of tai chi on lower urinary tract symptoms (LUTSs), quality of life (QoL), and sex hormone levels in patients with benign prostate hypertrophy (BPH). The elderly patients with BPH were randomized to receive tai chi or usual care. Fifty-six participants were randomized into either the tai chi group (n = 28) or the control group (n = 28). After 12 weeks of treatment, the tai chi group showed significant improvement in LUTS and QoL. There was a significant effect of tai chi on testosterone but no significant effect on insulin or glucose. No serious adverse events were observed during the study period. In conclusion, our results suggest that 12 weeks of tai chi may improve LUTS and QoL in elderly patients with BPH.