We have identified putative microtubule-organising centres in whole mounts and frozen sections of full term human placenta, amniochorion and first trimester chorionic villus tissue by indirect immunofluorescence confocal laser scanning microscopy. These sites may perform a crucial executive role in the morphogenesis of human extra-embryonic membranes, and also may establish polarity in the amniotic epithelium and mediate the branching pattern of growth essential to the production of the chorionic villus tree.