Cesarean scar pregnancy is a potentially dangerous consequence of a previous cesarean delivery. If unrecognized and inadequately managed, it can lead to untoward complications throughout all three trimesters of the pregnancy. The rate of occurrence parallels the mounting rate of cesarean sections. The late consequences of cesarean delivery, such as placenta previa and placenta accrete, were known for a long time. However, it took more than a decade for the obstetric community to make the connection between the cesarean scar pregnancy and the placenta accreta spectrum. This article discusses the pathogenesis and diagnosis of cesarean scar pregnancy.