Postmortem cesarean delivery is an operation that has been practiced since antiquity. In previous centuries low infant survival rates led to negative opinions regarding the operation's usefulness. A review of the past centuries' cases and a review of fetal physiology suggest that to obtain optimum infant survival, cesarean delivery should be initiated within four minutes of maternal cardiac arrest. The physiology of cardiopulmonary resuscitation during pregnancy is analyzed, and recent cases of maternal cardiac arrest with successful maternal resuscitation are reviewed. This data suggests that perimortem cesarean delivery initiated within four minutes of maternal cardiac arrest will yield the highest rates of maternal survival. Legal liability from the operation is minimal.