Lennox–Gastaut syndrome (LGS) is a severe developmental epileptic encephalopathy that presents anesthetic challenges because of refractory epilepsy, multiple antiepileptic medications. We report the anesthetic management of a 7-year-old boy with LGS who underwent elective tracheostomy for progressive upper airway obstruction. Preoperative evaluation revealed micrognathia, retrognathia, and dynamic upper airway obstruction, suggesting a potentially difficult airway. Antiepileptic medications were continued throughout the perioperative period, and general anesthesia was induced after preoxygenation with a HFNC (high-flow nasal cannula). Tracheal intubation was successfully performed using a McGrath MAC video laryngoscope, and anesthesia was maintained uneventfully with sevoflurane and remifentanil without perioperative seizure-related or airway complications. The patient recovered without anesthetic complications. This case highlights the importance of careful perioperative planning, including appropriate seizure management and airway preparation, for the safe administration of general anesthesia in pediatric patients with LGS.