Acetaminophen is a common drug used in pregnancy. A 32-year-old woman ingested 64 g of acetaminophen at 15 weeks of gestation. Treatment with N-acetylcysteine was given within 24 hours. The patient nonetheless developed severe hepatic necrosis and her hospital course was complicated by adult respiratory distress syndrome. With aggressive supportive treatment, the mother survived and delivered a viable infant at 32 weeks' gestation. The possible mechanisms of acetaminophen toxicity in the mother and the fetus are discussed.