We report three cases of neonatal haemangiomatosis associated with large placental chorioangioma. Pregnancies were complicated by polyhydramnios, and all mothers underwent amniocentesis to drain the liquid. Steroid treatment was required for two children. Although the theory has been largely disproved in normal haemangiomas, embolization of precursor endothelial cells derived from placental vessels is a likely explanation for the pathogenesis of haemangiomatosis associated with large placental chorioangiomas.