Micturitional histories and urodynamic studies were performed in 14 patients with syringomyelia. Eleven patients were revealed to have urinary symptoms including difficulty of voiding in 8, urinary retention in 3, nocturnal and diurnal urinary frequency in 3, urinary incontinence in 2, and sense of urgency and enuresis in one. These urinary symptoms appeared after 5.3 years (ranging from 2 months to 13 years) from the occurrence of the neurological symptoms. Urodynamic studies revealed detrusor hyperreflexia in 7, detrusor areflexia in 4, detrusor-sphincter dyssynergia in 4 and uninhibited sphincter relaxation in 2 patients. Analysis of the motor unit potentials of the external sphincter revealed 5 of 6 patients had high amplitude or polyphasic neurogenic changes. Supranuclear as well as nuclear types of parasympathetic and somatic nerve dysfunctions seemed to be responsible for micturitional disturbance in our patients with syringosubarachnoid shunts and in 3 of 4 after α-adrenoreceptor blocking agents.