Vascular endothelial cells form a natural antithrombogenic lining on all blood vessels. Replacement or bypass of small diameter blood vessels with artificial polymeric grafts has not been clinically acceptable due to the thrombogenic nature of polymeric material. One approach to improving the patency of vascular prosthetic devices has been the establishment of endothelial monolayers on the blood flow surface using the technique known as seeding. Scanning electron microscopy has been a major tool in evaluating the interaction of endothelial cells with polymeric surfaces resulting in a basic understanding of forces and structures regulating endothelium-polymer interactions. In-vitro and in-vivo studies have established the feasibility of using endothelial cell seeding technology in human clinical trials. This tutorial describes the development of endothelial cell seeding technology and illustrates how scanning electron microscopic evaluations have furthered our understanding of endothelial cell-polymer interactions.