Liver transplantation is the best therapeutic approach in patients with acute liver failure. This clinical presentation during pregnancy is an unusual and dramatic event. We report the case of a 18 year-old woman with cryptogenic acute liver failure who underwent successful orthotopic liver transplantation at 20 weeks of pregnancy. Both outcomes were analyzed. Fetal death was observed within 48 hours after liver transplant. After six months of follow-up, the patient is doing well. This case illustrates the challenge of treating acute liver failure during pregnancy and demonstrates that liver transplantation is a feasible therapeutic option for treatment of patient with this condition.