Prostatitis is a common genitourinary disease in men. The National Institutes of Health has defined four types of prostatitis. The bacteriology of acute and chronic bacterial prostatitis is well understood. Causative organisms can be isolated by four-glass urine cultures. Chronic pelvic pain syndrome (CPPS; chronic abacterial prostatitis) is an enigma; whether there is a microbiologic cause for this condition is unknown. Researchers have postulated that CPPS may be an infectious disease of the prostate. This article reviews current literature regarding the microbiology of the prostate in CPPS.