Ninety-five lower extremities in 53 patients underwent iliofemoral arteriography, high thigh wide cuff Doppler pressure measurements and direct intra-arterial pressure measurements at the common femoral level to determine the accuracy of the high thigh Doppler technique in the evaluation of aorto-iliac occlusive disease using the intra-arterial pressure as the standard. Results showed the high thigh cuff Doppler technique to be 79 per cent sensitive, 56 per cent specific and 63 per cent accurate in the evaluation of haemodynamically significant aorto-iliac disease. There was a false negative rate of 13 per cent, but a false positive rate of 59 per cent. All false positive tests were shown to be secondary to superficial femoral artery disease. These results indicate that a normal high thigh wide cuff Doppler pressure is generally reliable in ruling out haemodynamically significant aorto-iliac, occlusive disease at rest. An abnormal result, however, does not differentiate between aorto-iliac and superficial femoral artery disease.