The present study was designed to reveal the usefulness of acupuncture for chronic pelvic pain syndrome with intrapelvic venous congestion as evaluated by symptom scores, transrectal ultrasonography (TRUS) and magnetic resonance (MR) venography. Ten male patients suffering from non-inflammatory chronic pelvic pain syndrome (NIH category IIIB) with intrapelvic venous congestion were treated using acupuncture. Eight patients had previously received pharmacotherapy, which was unsuccessful. Acupuncture was performed using disposable stainless steel needles, which were inserted into the bilateral BL 33 points and rotated manually for 10 min. The treatment was repeated every week for 5 weeks without other therapeutic manoeuvres. Results from TRUS and MR venography, as well as clinical symptoms based on the NIH chronic prostatitis symptom index (NIH-CPSI) and the international prostate symptom score (IPSS), were compared before and after the treatment. No side-effects were recognised throughout the treatment period. The average pain and quality of life scores of the NIH-CPSI 1 week after the fifth acupuncture treatment decreased significantly (P < 0.05 and P < 0.01, respectively) compared with the baseline. The maximum width of the sonolucent zone 1 week after the fifth treatment also decreased significantly (P < 0.01, compared with the baseline). Intrapelvic venous congestion demonstrated by MR venography was significantly improved in four patients.