The use of botulinum toxin in paediatric urology has become increasingly widespread during recent years; however, the evidence base for its clinical use has been from adult urology centres and trials. The mechanism of action of this potent neurotoxin is discussed and evidence for its efficacy and safety is reviewed in both the adult and paediatric literature. Second, an electronic literature search was performed using the keywords paediatric urology, botulinum toxin, bladder, sphincter, and voiding dysfunction (excluding abstracts, letters and case reports). A total of 225 children in 10 peer-reviewed publications were evaluated with 165 paediatric patients with neurogenic overactivity (6 studies), 21 patients with idiopathic overactivity (1 study) and 39 patients with voiding dysfunction (3 studies). Specifically, we discuss the main indications of intravesical injections for detrusor overactivity and of intrasphincteric injections for refractory voiding dysfunctions in the paediatric population.