Detailed micturitional histories and urodynamic studies were performed in five patients with radiation myelopathy. All patients had micturitional symptoms that were irritative in five and obstructive in four, and four had urinary incontinence. Urodynamic studies showed that three patients had residual urine of 158 ml on average. Cystometry showed that four patients had detrusor hyperreflexia and one had low compliance cystometrogram. External sphincter electromyography showed that four patients had detrusor-sphincter dyssynergia. These results indicated that micturitional disturbance seemed to be common and severe in storage as well as evacuation function. The main responsible sites of lesions seemed to be supranuclear parasympathetic and somatic nervous systems regulating the lower urinary tract. Two of three patients who underwent combination of steroid pulse therapy and hyperbaric oxygen therapy experienced improvement of micturitional disturbance and other neurological deficits.