Patients included will have overactive bladder symptoms refractory to medical therapy. Other causes of overactive bladder symptoms including urogenital prolapse and recurrent urinary tract infections were excluded. None of the patients will be under anticoagulant therapy or drugs interfering with neuromuscular transmission. The study was approved by the local ethical committee and patients gave their informed consent. Patients will be informed about the possible need for intermittent catheterization after BoNT/A treatment.