ObjectiveTo determine the 9 month period effect of botulinum toxin A (BoNT-A) injection into the salivary gland in children with neurologic disorders and sialorrhea by qualified parent/caregiver-administered questionnaires.MethodA total of 17 patients (age 7.6±4.24 years) were enrolled in this study. The degree of sialorrhea was assessed at the baseline, 2 weeks, 1, 2, 4, 6 and 9 months after injection. The Drooling Count (DC) was assessed as an objective measurement. The Drooling Frequency and Severity Scale (DFS) and the Teacher Drooling Scale (TDS) were evaluated as a subjective measurement. BoNT-A (0.5 unit/kg) was injected into each submandibular and parotid gland under ultrasonography-guidance.ResultsDC, DFS and TDS showed significant improvement at 2 weeks, 1, 2, 4, 6, and 9 months follow-up (p<0.05). Twelve of 17 cases (70.5%) showed more than 50% reduction in DC from the baseline value.ConclusionUltrasonography-guided BoNT-A injection into the submandibular and parotid gland was a safe and effective method to treat sialorrhea in children with neurologic disorders.