In patients with venous hypertension due to postphlebitic syndrome or varicose veins skin changes, liposclerosis and ulcerations are associated with increased skin blood flux at rest, a decreased venoarteriolar response and increased capillary filtration. Using laser-Doppler flowmetry we studied skin flux and the venoarteriolar response in the perimalleolar region in 100 normal limbs, 100 limb with varicose veins and 100 postphlebitic limbs with edema, skin changes and liposclerosis. The venoarteriolar response was studied with the leg on dependency, the foot being 50 cm below heart level. Flux at rest and on dependency were increased and the venoarteriolar response decreased in both groups of patients at a significantly greater extent in postphlebitic limbs. In conclusion laser-Doppler flowmetry measurements differentiate between normal limbs and those with venous hypertension and between postphlebitic limbs and limbs with venous hypertension due to varicose veins. The increase in skin flux and decrease in venoarteriolar response may be useful to define and quantify the degree of microangiopathy and the effects of treatments in venous hypertension.