The dual autonomic innervation of the urinary bladder of the female rat was studied using histochemical and light and electron microscopic methods. The bladder body in the normal state had a rich supply of cholinergic nerve fibers with a uniformly reticular pattern, but it was sparsely supplied with adrenergic nerves mainly associated with the blood vessels rather than the detrusor muscles. Seven days after the unilateral extirpation of the pelvic ganglion, most cholinergic and adrenergic fibers on the ipsilateral side of the bladder body disappeared markedly with the use of enzymatic and fluorescent histochemical techniques. The acetylcholinesterase activity of cholinergic fibers and the intensity of fluorescence of adrenergic fibers were somewhat restored 14 days after the operation. Seventy days postoperatively, it was found that the former had recovered in the relatively fine nerve fibers, while the latter had been almost completely restored, compared with the normal adrenergic innervation of the bladder body.