We analyzed the frequency of vesicoureteral reflux and the factors that favor its appearance after kidney transplantation in pediatric patients. This retrospective analysis examined the prevalence of post-transplant vesicoureteral reflux in a total of 181 kidney transplants performed in children at our center between 1978 and 2004. In patients who required corrective surgery for this problem, we analyzed pretransplant residual diuresis, pretransplant pathology and post-transplant problems related to vesicoureteral reflux. We also analyzed form of presentation, whether reflux was to the graft or to the native kidney, degree of reflux, and surgical technique used to correct reflux. Ten patients (5.5%) needed surgery to correct reflux to the graft (nine children) or to the native kidney (one child). Reflux was manifested as urinary tract infection in six children and progressive graft failure in one. Urethrovesical disorders that favored vesicoureteral reflux were present in eight patients (non-compliance bladder, detrusor overactivity, posterior urethral valves, urethral stenosis). Lengthening the submucosal tunnel stopped urinary tract infections in all 10 patients, whereas six-month voiding cystourethrograms showed resolution in 8 patients and (only) reduction in the degree of reflux in two. The high percentage of post-transplant vesicoureteral reflux in pediatric patients were related with higher frequencies of ureterovesical pathology in children who received the transplant. Lengthening the submucosal ureteral tunnel vesicoureteral reflux was corrected in 80%. We recommend during implantation in children with pretransplant urethrovesical abnormality an initial technique, which utilizes a longer submucosal tunnel such as the Lich-Gregoir.