Purpose. The prospective study was aimed at estimating the value of duplex sonography for imaging arteries before arteriovenous fistula (AVF) construction and of evaluating the influence of this method on the outcome of fistula construction. Methods. A total of 35 patients with end stage renal disease were examined by duplex sonography (DS) before AVF construction, and 27 of them with patent AVF were examined 1, 7 and 21 days after the operation. Filling artery flow was evaluated at 8 and 12 weeks. All AVFs were constructed on the forearm using native veins. Direct measurements of the arterial internal diameter during the operation were also performed. Results. The mean internal diameter of the arteries (IDA) detected by sonography 2.3 ± 0.62 mm, with a direct measurement of 2.1 ± 0.52 mm (mean ± SD). The correlation coefficient of DS IDA with direct measurement IDA was 0.86. In group A (IDA ≤ 1.5mm), immediate patency of the AVF was present in 45% (5/11), and in group B (IDA > 1.5mm) 92% (22/24) (P < 0.001). Before the construction, the mean volume flow through the radial arteries was 22 ± 6.8 ml/min in group A and in group B 46 ± 6.3 ml/min (P < 0.01). If there was conversion of high-resistance triphasic Doppler flow signal to low-resistance biphasic flow signal after release of a fist (group D), the AVF was patent in 95% (21/22), compared with a 46% (6/13) rate of patency in the group without such a response (group C). In 27 patients with patent AVF fistula, arterial volume flow the first day after construction was 138.1 ± 10.1 ml/min in group A and 184.2 ± 12.6 ml/min in group B. After 1 week, the volume flow was 169 ± 11.1 ml/min and 202.4 ± 13.5 ml/min, respectively. After 3 weeks the arterial flow was 274.4 ± 17.3 ml/min, and 366.2 ± 39.6 ml/min, respectively. After 12 weeks, the arterial flow was 438.5 ± 87.7 ml/min in group A, and 561.8 ± 131.3 ml/min in group B. The patency rate after 12 weeks was 36% in group A and 83% in group B. Conclusions. Duplex sonography could be a useful non-invasive method to evaluate arterial vessels prior to AVF construction. The relevant parameters measured by duplex sonography to evaluate the potential patency of the AVF are the arterial internal diameter and changes in the arterial Doppler flow signal.