AbstractSuccessful pregnancy depends upon placental growth and development, which follows a specific spatial and temporal sequence. Hepatocyte Growth Factor (HGF) is a potent mitogen, morphogen and motogen to both endothelial and epithelial cell types and is linked to a tyrosine kinase, proto-oncogene,c-metreceptor. In‘normal’third trimester placentae (n=5) full thickness biopsies (obtained at Caesarean section), immunolocalisation andin situ hybridisationstudies were performed for HGF andc-met, respectively. HGF immunoreactive protein was present in mesenchymal core, the vaculosyncytial membrane (syncytotrophoblast) and the vascular endothelial cells of villous trophoblast. The HGFmRNA was present particularly strongly in the perivascular stromal cells surrounding the villous vasculature and the amnion/chorionic membranes. Immunoreactivec-metprotein was strongly localised to the endothelial cells lining the villous vasculature and the vasculosyncytial membrane. A relatively weak and diffuse hybridisation signal forc-met mRNA was present throughout the villous trophoblast, most pronounced in the vasculosyncytial membrane. These results indicate that HGF may serve as a paracrine mediator to control placental development and growth.