Prostatitis ranges from a straightforward clinical entity in its acute form to a complex, debilitating condition when chronic. It is often a source of frustration for the treating physician and patient. There are four classifications of prostatitis: acute bacterial, chronic bacterial, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic. Diagnosis of acute and chronic bacterial prostatitis is primarily based on history, physical examination, urine culture, and urine specimen testing pre- and post-prostatic massage. The differential diagnosis of prostatitis includes acute cystitis, benign prostatic hyperplasia, urinary tract stones, bladder cancer, prostatic abscess, enterovesical fistula, and foreign body within the urinary tract. The mainstay of therapy is an antimicrobial regimen. Chronic pelvic pain syndrome is a more challenging entity, in part because its pathology is poorly understood. Diagnosis is often based on exclusion of other urologic conditions (e.g., voiding dysfunction, bladder cancer) in association with its presentation. Commonly used medications include antimicrobials, alpha blockers, and anti-inflammatory agents, but the effectiveness of these agents has not been supported in clinical trials. Small studies provide limited support for the use of nonpharmacologic modalities. Asymptomatic prostatitis is an incidental finding in a patient being evaluated for other urologic problems.