It is reported on a 6-year-old boy, in whom 3 years after the appearance of a neurogenic disturbance of the urinary bladder a lipoma in the spinal canal of the inferior thoracic region was diagnosed myelographically. The operative removal of the growing and displacing fatty tissue which by a (congenital?) dural gap continued in epidural direction indeed resulted in a far-reaching regression of the paresis of the lower extremities, not, however, in an improvement of the urological picture of the disease. The renal insufficiency caused by the hydronephrosis was no more reversible, which emphasizes the importance of the early diagnosis of this relatively infrequent malformation.