We present 2 cases of prenatal hydroureteronephrosis and bladder outlet obstruction due to an obstructing ureterocele. Both neonates were stabilized and managed with early endoscopic decompression. Neither infant demonstrated significant function in the kidney ipsilateral to the ureterocele either before or after ureterocele puncture. There have been few cases reported of prenatal bladder outlet obstruction due to a ureterocele. Our limited experience has been poor with regard to salvaging the affected upper tract. Future definitive management will be tailored as more of these cases are documented.