Urinary symptom severity can be documented objectively among men with BPH using validated instruments such as the AUA Symptom Index. The AUA Index was developed to discriminate among BPH patients who are more or less bothered by their condition, and to measure change in symptom levels over time or with treatment. The AUA Index is reliable and valid for these purposes and can be useful in both clinical practice and research. The role of symptom measurement in general and the AUA Index in particular in the diagnosis of BPH is unclear and may be limited. Additional research is needed to maximize the utility of symptom measurement in urology.