Two cases of neurogenic bladder with pituitary adenoma are reported. The pituitary adenomas produced excessive GH (growth hormone). The etiology of the neurogenic bladder was not identified by X-ray examination or any other tests. Urodynamic study, however, indicated a functional cause of neurogenic bladder. Case 1 was a 55-year-old male, who had a relatively small pituitary adenoma with mild symptoms. Urologically, there was complete urinary retention. Cystometrogram showed a flaccid pattern, detrusor-sphincter dyssynergia in sphincter-EMG and ice water test was negative. Case 2 was a 67-year-old female, who had a large pituitary adenoma and severe symptoms. Cystometrogram showed an almost normal pattern, however, there was detrusor-sphincter dyssynergia and ice water test was negative. We suggested that the neuropeptide takes some part in the pathophysiologic cause of neurogenic bladder.