Bruits between epigastrium and popliteal fossae were found in 63% of 309 patients with arterial obstruction and in 7% of 149 patients without obstruction. In the former group, ankle systolic pressure at rest was abnormal in 85% of limbs with bruits, indicating a hemodynamic abnormality. In the majority of limbs with bruits and normal pressures at rest, an abnormal pressure response to exercise suggests that auscultation is useful in detection of even milder arterial lesions. Auscultation, after exercise and during compression of arterial branches distal to the bruits, may unmask stenotic lesions that do not produce audible bruits at rest and may localize bruit-producing lesions. This study indicates that peripheral auscultation is a valuable technique for assessing the arterial system in individual patients and for screening population groups.