Objective — to study the causes of recirculation syndrome and optimize surgical correction. Material and methods. There were 2329 procedures of formation and restoration of permanent vascular access in 2109 patients for the period from 1998 to 2018. Recirculation syndrome occurred in 66 (3.1%) patients. Instrumental diagnosis of the causes of recirculation syndrome included Doppler ultrasound of permanent vascular access (100%) and angiography in accordance with indications. All patients were divided into 4 groups. The first group included 39 (59.1%) patients with native arteriovenous fistula. The second group included 12 (18.2%) patients with high arteriovenous fistula (between the brachial artery and the cephalic vein). The third group included 10 (15.1%) patients with major vein transposition. Synthetic prosthesis to create an arteriovenous fistula was used in the fourth group (n=5, 7.6%). Results. In the first group, recirculation syndrome was caused by the presence of a large branch in close proximity to the arteriovenous anastomosis, its combination with significant stenosis of the anastomosis, hypoplasia of the outflow pathways of the fistulous vein. In the second group, the reasons were subclavian vein stenosis and dilated tributaries of the saphenous veins. In the third group, the main cause of recirculation syndrome was major vein stenosis in the upper third of the shoulder. In the fourth group, recirculation syndrome was caused by stenosis of the prosthetic-venous anastomosis. Conclusion. Recirculation syndrome in hemodialysis patients is usually caused by malfunction of permanent vascular access. Ultrasound or angiography may be successfully used to diagnose dysfunction. Effective treatment of this problem implies surgical or endovascular correction of permanent vascular access.