Introduction: Moyamoya disease (MMD) is an arteriopathy characterized by progressive stenosis of brain arteries. Neurological symptoms can range from headaches and dizziness to severe sensory and motor impairment. Revascularization surgery helps prevent repeated strokes and further brain damage. Two postoperative years, age up to six years, and certain comorbidities are recognized as risk factors for complications during the process of brain neovascularization. Anesthetic management of these patients is challenging since anesthesia can alter cerebral blood flow (CBF) and cause inadequate perfusion in affected areas. Case Presentation: We report the case of a six-year-old boy with MMD who underwent deep sedation with sevoflurane for a follow-up endocranial MRI. In addition to MMD, the boy had a genetic predisposition for thrombosis, an allergy to atropine, and was within the critical two-year postoperative period during which any alterations in CBF could lead to complications. We chose sevoflurane and oxygen for deep sedation because of its favorable profile on hemodynamics and its negative feedback effect on respiratory drive, which prevents anesthetic overdose, enables spontaneous breathing, and preserves normocarbia during the procedure. The procedure lasted two hours and was uneventful. The boy was discharged home two hours later. Conclusions: Although revascularization surgery in MMD has a high success rate, in 5% of patients, repeated strokes can occur, especially in high-risk groups such as our patient. Awareness of existing risk factors, along with careful pre-anesthesia preparation and a well-considered anesthetic plan, are mandatory to prevent alterations in blood flow and ischemic attacks.