The aim of this study was to evaluate the veno-arteriolar reflex in the gaiter area and in the big toe of patients with chronic venous insufficiency (CVI). Twenty patients with lipodermatosclerosis and CVI comprised the disease group, and twenty subjects without venous disease comprised the control group. The activity of the veno-arteriolar reflex in the gaiter area and in the big toe in the affected and unaffected limbs of patients with CVI, and in normal controls was assessed by calculating the percentage fall in skin blood flux on dependency as measured by Laser Doppler fluxmetry. The results showed that the veno-arteriolar reflex was normal in the gaiter area in both the affected limb and the unaffected limb in patients with CVI compared to normal controls, [median percentage fall in flux and interquartile range for affected limb in patients with CVI = 49 (35-69), for the unaffected limb of patients with CVI = 41 (24-58), for normal controls = 49 (31-57), p value (Mann-Whitney) for patient groups compared to normals = 0.52, 0.60 respectively]. However in the big toe the veno-arteriolar reflex was impaired in the affected limb of patients with CVI compared to both the unaffected limb and to normal controls, [median percentage fall in flux and interquartile range for affected limb in patients with CVI = 52 (29-64), for the unaffected limb of patients with CVI = 69 (45-78), for normal controls = 75 (51-80), p value (Mann-Whitney) for patient groups compared to normals = 0.017, 0.92 respectively].(ABSTRACT TRUNCATED AT 250 WORDS)