To evaluate the efficacy of acupuncture in drinkers with chronic prostatitis / chronic pelvic pain syndrome (CP/CPPS). We conducted a secondary analysis of a randomized controlled trial across multiple centers, involving 224 drinkers. Patients received either acupuncture or sham acupuncture treatment. The primary outcome was the proportion of responders, defined as participants who had a reduction of 6 points or more from baseline in the National Institute of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) total score at weeks 8 and 32. Secondary outcomes measures included the Global Response Assessment (GRA), International Prostate Symptom Score (IPSS) and International Index of Erectile Function 5 (IIEF-5). One hundred and twelve drinkers were included in each group (n = 224 in total). The proportion of responders in terms of NIH-CPSI was 58.9% versus 40.3% in the acupuncture group (AG) and sham acupuncture group (SAG), respectively, with a statistically significant difference of 18.6% (p = 0.002) at week 8. Higher proportions of responders with respect to NIH-CPSI (p < 0.001 at week 32) and GRA (p < 0.001 at week 8 and p = 0.01 at week 32) were observed in the AG compared with the SAG. No between-group differences were found in the changes in IPSS at any assessment time point. Changes in IIEF-5 score were significantly higher in the AG than in the SAG at weeks 20 and 32, while the difference was not statistically significant at week 8. Acupuncture appeared to alleviate the symptoms of pain among drinkers with CP/CPPS and improve their quality of life, but had no demonstrable effect on urinary tract symptoms or erectile function among these patients. NCT03213938 (ClinicalTrials.gov).