We present a 17-year-old man who underwent brain magnetic resonance imaging and laboratory exams for uncontrolled seizure. Patients with an autistic disorder require deep sedation or, occasionally, general anesthesia even for radiologic exams or simple procedures. The anesthetic management of an obese, violent patient with a severe autistic disorder and mental retardation can be challenging to anesthesiologists and requires a more careful approach in selecting adequate anesthetics and doses. This case emphasizes the importance of having a detailed plan to ensure the smooth process of premedication, anesthetic induction, maintenance, emergence and safe discharge of incorporated patients in the event of unexpected situations. A 5% lidocaine patch to relieve the pain from the intramuscular injection and intravenous cannulation, intramuscular midazolam as premedication, and propofol for the maintenance of sedation can be a good sedation protocol in incorporated patients.