An overactive neurogenic detrusor and an non-neurogenic overactive bladder both exhibit symptoms such as urgency and frequency, both with and without urinary incontinence, and are often accompanied by nocturia. OnabotulinumtoxinA-Detrusorinjection has become well established as a second line therapy in cases where anticholinergic medication has failed. The procedure can be performed under general or local anesthesia, in both in- and outpatient settings. The side effects of the procedure are primarily urinary tract infections and - especially in neurogenic bladder patients - urinary retention. This article focuses on the approved indications and summarizes the current scientific data.