ObjectiveTo discuss the clinical classification and treatment protocols of complete duplication of kidney and ureter in children. MethodsBetween March 2000 and February 2015, 106 children with complete duplication of kidney and ureter were treated, and the clinical data were retrospectively analyzed. Of them, there were 11 boys and 95 girls, aged from 1 month to 11 years (mean, 3.5 years); one side was involved in 88 cases and two sides in 18 cases. They were divided into 4 types according to image examinations and clinical presentations:14 patients who needed no special treatment were classified into the first type, 15 patients who underwent reconstruction into the second type, 74 patients who underwent segment removal of renal dysplasia and subtotal excision of abnormal duplicated ureter into the third type, and 3 patients who underwent removal of the whole affected kidney and subtotal excision of whole ureter into the forth type. ResultsThe patients were followed up 2 months to 14 years (median, 23 months). There was no deteriorating case in the first type. There was no complication such as leakage of urine, discomfort over the back and loins, ureterocele, reproductive tract infection, or hematuresis in the other types. The results of white blood cell count, renal function, and electrolyte presented no abnormality. One patient in the second type and 6 patients in the third type had ureteral stump syndrome; 1 patient in the second type and 3 patients in the third type had urinary tract infection; and 3 patients in the second type had mild hydronephrosis after operation. ConclusionIt can obtain good clinical outcome to choose individualized treatment according to clinical classification of complete duplication of kidney and ureter, which can reserve effective renal units as much as possible and improves the patients' quality of life.