Mirror syndrome is a rare disorder in which fetal hydrops is associated with maternal oedema, proteinuria and hypertension. The aetiology of the maternal condition is unknown, but it is thought to be related to preeclampsia. Few descriptions exist of placental morphology in mirror syndrome, but placentomegaly is consistently observed. In this case placental morphology showed villous oedema and syncytial nuclear aggregates where villi were in direct contact. Immunoperoxidase staining for VEGFR1 and Endoglin was more intense in mirror syndrome compared to gestational-age matched controls,and at a similar level to a case of preeclampsia. Placentally-derived anti-angiogenic factors may be involved in the pathogenesis of mirror syndrome.