If a ureterocele is not diagnosed using prenatal ultrasound, it may become apparent during infancy. The most common presentation is a urinary tract infection, which results from urinary stasis in the obstructed system. Less often, a ureterocele can cause failure to thrive, flank pain, or hematuria. If the ureterocele lies within the bladder neck, voiding dysfunction may occur. If the obstruction and associated hydronephrosis are severe, the kidney may become a palpable abdominal mass.

The diagnosis of ureterocele is typically established using ultrasound. In most cases, ureteral duplication is also seen. Hydroureteronephrosis may be seen if there is an obstruction. The diagnosis may be missed if the bladder is overdistended with urine because the ureterocele may become effaced. In addition, it is important to distinguish between a ureterocele, which is separated from the bladder lumen by its own thin wall, and a dilated ectopic ureter, which is separated from the bladder lumen by the thicker bladder walls.