Percutaneous/intrathecal chemical neurolysis of sacral nerve with 12% phenol was performed on 13 cases of hyperreflexic bladder to augment bladder capacity and to reduce bladder pressure. Urodynamic evaluations were done before and after chemical neurolysis. Mean bladder capacity increased significantly after chemical neurolysis (from 171.4 ml to 375 ml). No significant changes in bowel or injection sites were noted. The result suggests that the chemolysis of sacral nerve was available modality for hyperreflexic bladder patients, who did not respond to anticholinergic medication, before decide the more aggressive alternatives such as augmentation cystoplasty or urinary diversion.