We studied the effect of acupuncture on a case of neurogenic impotence caused by surgery for ano-rectal cancer. Acupuncture needles (length: 60mm, diameter: 0.3mm) were inserted into bilateral Zhongliao (BL33) and were stimulated erectrically or rotated manually for 10 minutes. The effectiveness of acupuncture was evaluated by IMP DIARY, which was consisted of the rate of increase on Erectometer, and the changes of the subjective symptoms. We also investigated the effects of acupuncture stimulation on microcirculation of the glans penis. After the treatmeent, IMP DIARY showed improvement of nocturnal penile tumescence, morning erection and erection by masturbation. The microcirculation at the glans penis was increased significantly immediately after acupuncture therapy. From these results, acupuncture treatment to the BL-33 points for neurogenic impotence after surgery for ano-rectal cancer was considered to be useful.