Methods and compositions for treating narcolepsy are provided which include administering gaboxadol or a pharmaceutically acceptable salt thereof to a patient diagnosed with narcolepsy. Also provided are methods and compositions for treating narcolepsy which include administering to a patient in need thereof gaboxadol or a pharmaceutically acceptable salt thereof, in combination with one or more of a CNS stimulant, a eugeroic agent, an antidepressant or a GABAB receptor agonist.