The endometrial blood vessels form a vascular bed with a number of unusual properties. Unlike most adult vasculature these blood vessels undergo constant cycles of growth and regression during the reproductive life of the female. This short review covers a number of different aspects relating to endometrial vascular structure and function during endometrial growth, implantation, endometrial regression and menstruation. Video footage from in-vivo microscopy of the rat endometrial subepithelial capillary plexus on the morning of day 6 of pregnancy is included in the CD-ROM. This shows the dramatic changes that occur to the endometrial capillaries at the time of embryo implantation.