ABSTRACT Purpose Current practice in reconstruction of the lower urinary tract for duplicated renal systems with an associated ureterocele is excision of the ureterocele with reconstruction of the bladder and a common sheath ureteroneocystostomy. For a nonfunctioning upper pole treatment is partial nephroureterectomy. We postulate that lower urinary tract reconstruction can be performed successfully through an extravesical approach without excision of the ureterocele or reconstruction of the bladder base. We present our experience with that approach. Materials and Methods Between 1996 and 2001, 60 patients presented with the diagnosis of ureterocele and obstruction of the upper pole ureter. Partial nephrectomy was performed in 12 cases of which 4 had reflux to the lower pole moiety. Upper pole only dismembered ureteroneocystostomy was performed in 7 of 15 cases reconstructed using the extravesical approach. Results Average postoperative stay was 3.7 days. The Foley catheter was removed within 24 to 48 hours. Postoperative ultrasound showed decompression of the obstructed system and the ureterocele. Reflux was corrected in all patients. Flow rate with measurement of post-void residual 6 weeks postoperatively in toilet trained children showed complete bladder emptying. Conclusions Lower urinary tract reconstruction for duplicated renal systems with obstruction of the upper pole can be accomplished safely with decreased morbidity through the extravesical approach without excision of the ureterocele or reconstruction of the bladder base. Moreover, in instances when there is no reflux to the lower pole moiety, upper pole only extravesical ureteroneocystostomy can be performed.