Budd-Chiari syndrome during pregnancy has rarely been reported. This report presents a case of acute hepatic failure in a 20-year-old pregnant woman attributable to Budd-Chiari syndrome with underlying resistance to activated protein C caused by factor V Leiden mutation. The patient delivered a healthy girl by cesarean section in the 31st week of pregnancy. Acute hepatic failure in the 6th week postpartum was successfully treated by emergency liver transplantation, and the patient and her child were doing well at 8-month follow-up. Liver transplantation was lifesaving; normal factor V production by the transplant corrected the underlying coagulopathy. In this patient, latent thrombophilia attributable to activated protein C resistance was apparently aggravated by the hypercoagulable state of pregnancy leading to acute Budd-Chiari syndrome. Activated protein C resistance should be sought as an etiologic factor in patients with Budd-Chiari syndrome.