A new surgical technique is presented for treatment of affected ureter of the lower half of the double kidney consisting in lumbotomy, mobilization of the kidney and both ureters, followed by cutting off the ureter of the lower half of the double kidney from the pelvis and removal of the ureter. The ureter of the upper half is crossed at the distance of 5 cm from the pelvis and anastomosed with the pelvis of the lower half of the double kidney, its distal part is sutured with the lower part pelvis by Andersen-Hynes. As a result, two wide anastomoses of the proximal and distal parts of the ureter of the upper half of the double kidney with pelvis of its lower half is created. Drainage of the connected urethra is conducted separately with nephrostomic drainage, intubator and stent. Such surgical aid allows urine flow from both halves of the double kidney along one unaffected ureter of its upper half. Two women were operated by the above technique: a 53-year-old woman had iatrogenic lesion of the ureter of the lower half of the double kidney causing its extended defect; the other 21-year-old woman had a vesicoureteral reflux to the lower half of the kidney. Urodynamics of the upper urinary tract recovered in both the patients. Thus, upper ureteropyeloureteroanastomosis in complete doubling of the upper urinary tract and obstruction of the ureter of the lower half of the kidney reestablishes adequate urine outflow in the above anomaly by the unaffected ureter.