Purpose of reviewThis review covers recent developments in the classification, epidemiology, aetiology, diagnosis and treatment of patients diagnosed with chronic prostatitis (NIH classification types II, IIIa/IIIb and IV prostatitis) in the period of review (2001-2002).Recent findingsRecent studies highlight some of the problems with the 1995 NIH classification. Epidemiological studies have confirmed that ‘prostatitis’ is common, with a prevalence of 10-15%. Associations of prostatitis include benign prostatic hyperplasia, sexually transmitted disease, lower urinary tract symptoms, stress, and reduced sunlight exposure. Elevated levels of cytokines in the seminal plasma and prostatic secretions have been detected in men with chronic prostatitis compared with normal individuals, suggesting an active inflammatory process in the male genital tract. This inflammatory reaction may be mediated by an adaptive immune response directed against a genital tract antigen(s) (autoimmunity). Increased levels of bacterial 16S ribosomal DNA in the prostates of men with chronic prostatitis compared with controls are compatible with the notion that a bacterial inflammatory event initiates an auto-immune process; however, the role of bacteria in the continuation of symptoms is unknown.SummaryThe aetiology of chronic pelvic pain syndrome is still not certain, although an auto-immune process is favoured. Further research is required to determine the putative auto-antigen, the immune responses of patients, the role of bacteria in the inflammatory process, and the patients' pain response to genitourinary insults. As yet no diagnostic tests (other than to eliminate other pathology) and few treatments for chronic prostatitis can be recommended on the basis of scientific evidence.