Neurogenic detrusor overactivity can cause urgency and urinary incontinence in multiple sclerosis and spinal cord injury despite oral antimuscarinic therapy. In this prospective double-blind multicentre trial, patients with persistent urinary incontinence were randomized to intradetrusor onabotulinumtoxinA or placebo. Active treatment reduced the frequency of daily urinary incontinence and improved validated quality-of-life measures during the primary follow-up period. The study provides strong evidence for botulinum toxin as a local therapy when oral medication does not adequately control neurogenic bladder symptoms. The clinical trade-off is the risk of urinary retention, which may necessitate intermittent catheterisation. For HCPs, the practical pathway is therefore to assess bladder-emptying function before treatment and counsel patients about catheterisation if necessary. The intervention should form part of a broader neuro-urological assessment rather than being used solely to suppress urgency. The findings are directly relevant to IANCON's neuro-urology workshop, which addresses assessment and management of neurogenic bladder and sexual dysfunction in neurological patients.