We reviewed the cases of 95 children with duplex ureteroceles treated in this department over an 18-year period. There were 101 ureteroceles (6 bilateral). Diagnosis and treatment were analyzed. Special attention was paid to newborns screened in utero. We always strove to preserve functional renal tissue whenever possible. In keeping with this goal, three surgical techniques were used: (1) upper pole heminephrectomy; (2) ureterocele excision, bladder neck reconstruction, and ureter reimplantation with or without cutaneous ureterostomy of the upper pole ureter; and (3) endoscopic ureterocele incision. Follow-up studies using x-ray and radionuclide imaging demonstrated satisfactory renal function in 86.6% of patients. These findings support a conservative approach to ureteroceles using endoscopic ureterocele incision as the primary treatment. Lower urinary tract reconstruction may be associated in cases involving urinary tract infection, obstruction or incontinence. Upper pole heminephrectomy should be performed only after functional evaluation following ureterocele incision or cutaneous ureterostomy.