This study measured the hemodynamics of peripheral arterial sites in the rat, using 20 MHz pulsed ultrasonic Doppler velocimeter (PUDVM) methods. The lower extremities of 14 male Sprague-Dawley rats were studied. The targeted sites included the abdominal aorta, external iliac, proximal femoral, mid-femoral, and saphenous arteries. The hemodynamic variables of pulse period, maximum centerline velocity, lumen diameter, and mean volumetric flow were calculated interactively from temporal-spatial plots of local velocity distributions. An analysis of variance revealed significant differences between right and left sides for lumen diameter (P = 0.028) and mean volumetric flow (P less than 0.0001). The analysis showed no statistical difference for pulse period (P = 0.0836) among sites. However, three distinct groupings of sites: 1) abdominal aorta, 2) external iliac, proximal femoral, and mid-femoral arteries, and 3) saphenous artery were noted for the remaining hemodynamic variables (P less than 0.05). These results indicate that three hemodynamically distinct regions are available for microvascular research in the rat lower extremity arterial tree.