Conventional teaching has maintained that the detrusor musculature is well-coupled and unilateral innervation should prompt a coordinated detrusor contraction. We present the case of a 17-year-old girl with a tethered spinal cord, unilateral neurologic symptoms and fluoroscopic evidence of ipsilateral hemiparesis of the bladder unresponsive to cord detethering. This adds to a small body of evidence that the bladder smooth muscle is less well-coupled than once believed.