Physiological measurements are reported on patients with arteriomegaly, a condition in which the arteries are abnormally dilated, tortuous, and lengthened. The calf blood flows at rest and after ischaemia were found to be slightly increased compared with a control group. The blood volumes were significantly increased. The arm-to-arm circulation time was only marginally longer, but the velocity of arterial blood flow from the abdominal aorta to the knee was significantly slower than in the control group.