The development of persistent gestational trophoblastic disease following an apparently uncomplicated term pregnancy is well-recognized; however, reports of confirmed intraplacental choriocarcinoma are rare. We report four cases of histologically reviewed intraplacental choriocarcinoma occurring in third-trimester pregnancies from the files of a regional trophoblastic disease unit. In all cases, macroscopic examination of the placenta appeared unremarkable, with small nondescript lesions being identified, thought to be fresh infarcts or intervillus thrombi. Histological examination demonstrated the presence of focal intraplacental choriocarcinoma. Review of the literature demonstrates primary intraplacental choriocarcinoma rarely may be associated with obstetric complications such as intrauterine death or fetal distress. But in most cases, the disease is initially asymptomatic, the diagnosis only being made following histopathological placental examination for other indications. Intraplacental choriocarcinoma may therefore manifest as a spectrum of clinical disease ranging from an incidental lesion diagnosed on placental pathological examination with no adverse effects on mother or baby, through to metastatic maternal disease that is present in about half of the cases, to disseminated fatal infantile choriocarcinoma.