The etiology of chronic prostatitis/chronic pelvic pain syndrome is unknown. Whereas infection causes category I and II prostatitis, the evidence for an ongoing infection in category III patients is lacking. Immunologic, neurologic, and psychologic factors likely play a role in the development and maintenance of symptoms in these men. The traditional concept of pain as a simple response to a noxious stimulus has some merit, but modern research indicates that the response is much more complex, and we must look at a patient's physiology and psychology to be able to interpret each individual's pain response. It is some advance in the field to realize that we probably need to look beyond the prostate and address the entire biopsychosocial problem to be able to offer successful treatment to these men.