Previous experiments demonstrated that the vestibular system contributes to regulating sympathetic nervous system activity, particularly the discharges of vasoconstrictor fibers. The present study examined the physiological significance of vestibulosympathetic responses by comparing blood flow and vascular resistance in the forelimb and hindlimb during head-up tilts from the prone position before and after the removal of vestibular inputs through a bilateral vestibular neurectomy. Experiments were performed on conscious felines that were trained to remain sedentary on a tilt table during rotations up to 60° in amplitude. Blood flow through the femoral and brachial arteries was recorded during whole-body tilts using perivascular probes; blood pressure was recorded using a telemetry system and vascular resistance was calculated from blood pressure and blood flow measurements. Sixty degree head-up tilts in vestibular-intact animals produced an 20% decrease in femoral blood flow and an 37% increase in femoral vascular resistance relative to pre-tilt baseline levels; similar effects were also observed for the brachial artery (an 25% decrease in blood flow and an 38% increase in resistance). Following the removal of vestibular inputs, brachial blood flow and vascular resistance during head-up tilts were virtually unchanged. In contrast, femoral vascular resistance increased only 6% from baseline during 60° head-up rotations delivered in the first week after elimination of vestibular signals and 16% in the subsequent 3-week period (as opposed to the 37% increase in resistance that occurred prior to lesions). These data demonstrate that vestibular inputs associated with postural alterations elicit regionally-specific increases in vascular resistance that direct blood flow away from the region of the body where blood pooling may occur and support the hypothesis that vestibular influences on the cardiovascular system serve to protect against the occurrence of orthostatic hypotension.