The ulnar arterial circulation to bilateral hands of 683 men and 787 women was assessed with the Allen radial artery compression test. Of the 2,940 arms, the Allen test showed abnormalities in 105 (3.6%). The incidence of abnormality generally increased with age: 2.2% in the first decade and 6.9% after the ninth decade. It is very likely that circulatory failure in the hand develops after several decades among those whose radial artery was removed in their youth. When the radial artery is removed in the young, attention should therefore be paid to future consequences.