We review new data on the epidemiology of chronic prostatitis. These population-based studies used reasonable case-definitions to survey various populations from North America, Europe and Asia. Overall, 2-10% of adult men suffer from symptoms compatible with chronic prostatitis at any time and approximately 15% of men suffer from symptoms of prostatitis at some point in their lives. Other epidemiologic data suggest that chronic prostatitis may be associated with an increased risk for development of benign prostatic hyperplasia and prostate cancer. These data suggest that chronic prostatitis is an important international health care problem that merits increased priority from clinicians and researchers.