['Although chronic pelvic pain syndrome impairs the life of millions of people worldwide, the exact pathomechanisms involved remain to be elucidated. As with other chronic pain syndromes, the central nervous system may have an important role in chronic pelvic pain syndrome. Thus, we assessed brain alterations associated with abnormal pain processing in patients with chronic pelvic pain syndrome.', 'Using brain morphology assessment applying structural magnetic resonance imaging, we prospectively investigated a consecutive series of 20 men with refractory chronic pelvic pain syndrome, and compared these patients to 20 gender and age matched healthy controls. Between group differences in relative gray matter volume and the association with bother of chronic pelvic pain syndrome were assessed using whole brain covariate analysis.', 'Patients with chronic pelvic pain syndrome had a mean (± SD) age of 40 (± 14) years, a mean NIH-CPSI (National Institutes of Health Chronic Prostatitis Symptom Index) total score of 28 (± 6) and a mean pain subscale of 14 (± 3). In patients with chronic pelvic pain syndrome compared to healthy controls there was a significant reduction in relative gray matter volume in the anterior cingulate cortex of the dominant hemisphere. This finding correlated with the NIH-CPSI total score (r = 0.57) and pain subscale (r = 0.51).'] Is chronic pelvic pain syndrome in men associated with reduction of relative gray matter volume in the anterior cingulate cortex compared to healthy controls?