14 children with tethered spinal cord syndrome undergoing neurosurgical untethering were urodynamically evaluated in the pre- and postoperative period. The tethered spinal cord syndrome was mainly due to a previous surgical repair of meningomyeloceles. Preoperatively a neurogenic bladder dysfunction was found in 8 patients; postoperatively a transient amelioration could be demonstrated in 3 patients, whereas 2 children developed urinary retention, 1 of whom had never any complaint of bladder symptoms before. Thus, a high incidence of bladder dysfunction was revealed in children with tethered spinal cord syndrome, demonstrating substantial changes of the bladder function following neurosurgical intervention. With regard to these results a urodynamic evaluation should be part of the pre- and postoperative examinations in children with a tethered spinal cord syndrome.