Attention deficit hyperactivity disorder (ADHD) is characterized by inattention, impulsivity, and hyperactivity. Given high incidence of ADHD, many children with ADHD is likely to present for anesthesia. This case report suggests intramuscular premedication as an alternative method for anesthetic induction. A 9-year-old male patient with ADHD was transferred for dental treatment under general anesthesia. The patient refused to go into dental clinic office. Oral midazolam was given to the patient, however, he was resistant to take midazolam via oral route. Instead, we administer midazolam and ketamine via intramuscular route. After less than 10 miniutes, the patient became drowsy and was transferred to dental chair. Intravenous access and mask inhalation was possible. The patient received dental treatment under general anesthesia and recovered in a non-complicated way. In this case, intramuscular sedation with midazolam and ketamine was used as a premedication in highly uncoopearive patient refused to take oral sedative medication.