Surgical complications during kidney transplantation can seriously affect renal outcomes. We assess occurrence, risk factors, and results of all urological complications in a series of renal transplants in a single center. Children who underwent renal transplant between January 2008 and December 2014 were retrospectively evaluated. Postoperative urological complications were reviewed. Demographic details, cause of ESRD, donor type, and surgical procedures at transplant were analyzed. For statistical analysis, the chi-square test or Fisher's exact test were used as appropriate. One hundred and twenty-one kidney transplants were performed in 117 children (median age 12 yr). Sixty-two of 121 (53%) had an underlying urological malformation. At a median follow-up of three yr, 28 urological complications were recorded (23%): 12 lymphocele (10%), 10 ureteral obstruction (8%), three urinary leakage (2.5%), two symptomatic VUR (1.7%), and one hydropyonephrosis. When lymphocele was excluded, the complication incidence rate dropped to 13%. Ureteral obstruction mostly occurred late after transplant (more than six months). Presence of urological malformation was the only factor related to increased occurrence of urological complication (p = 0.007) and, in particular, ureteral obstruction (p = 0.018). Children with urological malformations presented a statistically significant risk of developing urological complications after kidney transplantation, ureteral obstruction being the most common complication.