Background: Presently, no study has been conducted using dexmedetomidine as single agent at maximal dose for drug-induced sleep endoscopy (DISE) under near infra-red spectroscopy (NIRS) monitoring. Case Report: Following adenoidectomy for obstructing sleep apnea (OSA), a pediatric patient complained of “absence like” epilepsy. EEG confirmed an epileptiform focus and polysomnography evidenced persistent OSA. To exclude upper airway obstruction, we performed an uneventful DISE under ASA standard monitoring and cerebral NIRS, using DEX as single anesthetic. NIRS evidenced baseline oxygen saturation asymmetry linked to the epileptic focus, which symmetrically slightly decreased during DEX induction, but then remained steady throughout the prolonged examination under DEX as sole anesthetic. Hemodynamic and respiratory profiles did not require any compensatory intervention throughout the examination. Conclusion: According to our finding, DEX even at higher than recommended dose, appears effective and safe as single anesthetic in DISE for OSA in a pediatric epileptic patient.