Galectins regulate many cell functions important for placental development, however, the localization and role of galectin-7 is unknown. We hypothesized galectin-7 would be expressed by the placenta and detected in serum. Galectin-7 immunolocalized to syncytiotrophoblast, extravillous trophoblast and glandular epithelium in 1st trimester placenta/decidua and to syncytiotrophoblast and endothelial cells in term placenta, but in pre-eclamptic placentas endothelial staining was absent. Galectin-7 serum concentration was significantly elevated in women (weeks 10-12 and 17-20) who subsequently developed pre-eclampsia compared to women with healthy pregnancies. Galectin-7 is a promising prospective serum biomarker for pre-eclampsia and likely has important functions in placentation.