The gag reflex is a physiological reaction, but, an exaggerated gag reflex can be a severe limitation not only to treat dental caries but also to do oral exam. Procedures such as surface anesthesia of the palate and pharyngeral area, sedation, or general anesthesia can be options as behavioral management. But, there are no golden rule for the sever gag reflex patients. We present a case report of propofol intravenous sedation using TCI pump for simple dental treatment. A 44-year-old man, who had past history of general anesthesia for dental treatment because of severe gag reflex, was scheduled intravenous sedation for simple dental treatment. After 8 hour fasting he entered the clinic for persons with disabilities. We explained about intravenous deep sedation and got informed consent. First, we kept intravenous catheter (22G) in the arm and started monitoring ECG, non-invasive blood pressure, pulse oximetry and end-tidal $CO_2$ through nasal cannula. We started propofol infusion with TCI pump at the target concentration of 3 mcg/ml. The patient became sedated, but he showed involuntary movement during dental treatment, so we increased the target concentration to 4 mcg/ml. We finished the dental treatment without complications during 30 min. And after 40 min recovery room stay he was discharged without any complications.