The treatment of detrusor hyperactivity still constitutes one of the great failures of twenty years urodynamic research, of this disease still requires many studies and research in order to more dearly understand as its mechanisms, and its etiologies and to define a more effective and specific therapy. The cures, suggested at the present time, as preliminaries to this pathology, are bladder anticholinergics, oxybutynin and retraining with or without biofeedback. The treatment for hyperactive bladder refractory to these usual treatments includes sub-trigonal injection of phenol or ethanol which constitutes a simple and effective method, less invasive than the other surgical methods which are generally used. The results of this method are satisfactory, for one year, in 40 % of cases and complications occur for 13 % of patients.This morbidity would decrease if a more rigorous selection of patients were undertaken. Patients previously treated by pelvic radiotherapy or surgery constitute a contraindication to this technique. Similarly, special precautions should be taken in men and when a large amount of these products is injected. Otherwise, it is essential to warn patients of the risks which this technique, involves, particularly urine retention, impotence and fistulas.