Narcolepsy is characterized by the excessive daytime sleepiness. In most cases, cataplexy also accompanies to narcolepsy and is called as narcolepsy-cataplexy syndrome. A-5-year-old boy was brought to our hospital due to drop attacks which had occurred two-three times in a week for one year when he was playing. It was learned that the patient had excessive daytime sleepiness while playing, and after these attacks he had continued to play again. After the reevaluation of the history and physical examination, he was diagnosed as narcolepsy. Imipramine treatment was begun. After two months of imipramine treatment, the symptoms were resolved.