In order to elucidate the parasympathetic activity of the uninhibited neurogenic bladder, controlled cystometry before and during influence of cholinergic and anticholinergic drugs has been performed on patients with normal and uninhibited neurogenic bladder. Cholinergic stimulation proved to increase the intravesical pressure to a great extent; to a higher degree in the normal than in the uninhibited bladder. In two patients with normal bladder, uninhibited detrusor contractions were induced by cholinergic stimulation. Cholinergic inhibition had only minor influence on the intravesical pressure during the filling phase. Opposite effects were obtained on the uninhibited detrusor contractions which are regarded as a part of the expulsive phase. Cholinergic stimulation increased the amplitude of the uninhibited bladder to some degree, but cholinergic inhibition markedly reduce the amplitude. Conclusively, the uninhibited neurogenic bladder is at least partly caused by an overactivity in cholinergic stimulation.