BACKGROUND: Glutaric aciduria type II is a rare disorder affecting the metabolism of fatty acid oxidation and several mitochondrial dehydrogenase enzymes. Narcolepsy and cataplexy is a disorder affecting sleep cycles and rapid eye movement activity. There is little information on outcome or management for either disorder in pregnancy. CASE: This is a case of a 16-year-old with glutaric aciduria type II and narcolepsy with cataplexy, treated with L-carnitine, riboflavin, fluoxetine, and modafinil during pregnancy. Intrapartum management included intravenous carnitine administration, and the patient underwent cesarean delivery at term without complication. CONCLUSION: This inborn error of metabolism and sleep disorder can be effectively treated during pregnancy with nutritional supplementation and stimulants. Because of the risk of cataplexy during labor, cesarean delivery is recommended to minimize the patient's risk.