Introduction. Ureteropelvic junction obstruction (UPJO) is defined as a blockage or obstruction of urine flow from the kidney into the proximal upper ureter that can lead to an increase in backpressure on the kidney, hydronephrosis, and progressive damage of the kidney function. The incidence of crossing vessels in patients with UPJO varies in the literature from 11% to 87%. Knowing about this anatomical situation preoperatively is important in the choice of therapeutic strategy and surgical technique. Preoperative diagnosis of the crossing vessels could determine the option for endoscopy, laparoscopy, or open surgery so as to have better control of the abnormal vessel. Aim of the study. The goal of this study was to assess the use of Computed Tomography (CT) for the detection of crossing vessels in patients with UPJO. Materials and methods. We analyzed prospectively 35 patients with UPJO diagnosed by CT, and treated by Hynes-Anderson pyeloplasty or nephrectomy in the Department of Urology, Dialysis and Renal Transplantation of the Republican Clinical Hospital between 2010 and 2014. Contrast-enhanced CT was performed by using arterial, venous, and excretory phases. The results obtained by imaging examination were compared with intraoperative aspects. Results. From 35 patients, crossing vessels were identified in 15 (42.85%) cases. There were 10 males and 5 females with mean age 36.86 years (range 23 – 62). II degree of hydronephrosis was identified in 4 (26.6%) patients, III degree in 10 (66,7%) patients and IV degree in 1 (6,7%) patient. After comparing the intraoperative and imaging results, we obtained that contrast-enhanced CT has proven to be 100% sensitive for detecting crossing vessels. By using CT, we were able to identify the position, type and number of vessels. Conclusions. CT is a valuable and accurate single-imaging method for preoperative diagnosis of crossing vessels associated with UPJO. It has the advantage of providing images that are easily understood and shows additional findings.