Posterior spinal fusion surgery for congenital scoliosis may cause substantial surgical trauma. Erector Spinae Plane Block (ESPB) can alleviate pain in adults who undergo spinal surgery; however, reports regarding its use in paediatric patients are limited. Here, we report the case of a 2-year-old girl who underwent posterior spinal fusion for congenital scoliosis. The patient initially experienced severe sadness upon separation from her parents; however, after performing various interactive activities, premedication using intranasal dexmedetomidine and midazolam was administered to sedate the patient. Ultrasound-guided bilateral ESPB was applied for perioperative analgesia. The anaesthesiologist identified mild-to-moderate pain during the first 6 days after surgery using the visual analogue scale for pain and Face, Legs, Activity, Cry, and Consolability scale. Therefore, ESPB may provide a satisfactory analgesic effect and help reduce postoperative opioid consumption in children who require spinal fusion surgery.