The usefulness of using the bispectral index (BIS) for monitoring during cardiopulmonary resuscitation (CPR) is not clearly understood. However, BIS has been a popular anesthetic monitoring device used during operations. The case presented is of a pregnant woman going into cardiac arrest due to an amniotic fluid embolism during a Cesarean section. CPR was performed, but neither the return of spontaneous circulation (ROSC) nor the return of consciousness was achieved, despite 50 min of effective CPR. However, CPR was continued based on BIS. ROSC was achieved, and an alert consciousness state was reached 1 day postoperation. This finding suggests that BIS be used as a basic monitoring device during CPR and that it may help in deciding to continue CPR.