Purpose : To evaluate the usefulness of venous dialysis pressure(VDP) and urea recirculation rate (URR) for the early detection of venous stenoses, the most common cause of hemodialysis fistular failure. To correlate the outcome of early percutaneous transluminal angioplasty(PTA) with VDP and URR after PTA. Materials and Methods :Eighty one chronic hemodialysis patients were monitored for VDP and URR during each session of hemodialysis treatment. Twenty-eight patients with elevated VDP and URR underwent fistulography, and the results were prospectively analysed. PTA was performed in twelve discrete stenoses (>70% reduction of the lumen) in six patients. Following PTA, VDP and URR were reevaluated. Result : Fistulogramas showed that 15 of 28 patients had 22stenoses. All of these lesions occurred in the proximal vein of an arteriovenous fistula, showing less than 50%reduction of the lumen in six stenoses, 50-70% in four, more than 70% in twelve, and no complete occlusion. Stenosis length was less than 1cm in twelve lesions, 1-3cm in seven, and 3-6cm in three. In 11 of 12 stenoses, angioplasty was successful with no significant residual stenosis remaining. After PTA, mean VDP and URR fell significantly : 117.8$pm$20.6 mmHg to 99.8$pm$ 8.2 mmHg (p=0.025), and 22.9$pm$16.1 to 7.6$pm$7.2(p=0.014), respectively.Conclusion : Early detection and early PTA of venous stenoses led to a high initial patency rate when used in conjuction with elective measurement of VDP and URR. After PTA, VDP and URR fell significantly, and there was close correlation with the outcome of PTA.