Successful clinical application of compound materials should involve detailed investigations on interaction between material and tissue. A desirable feature of scaffolds is the ability to support new blood vessel growth. With the present investigation, we examined the behaviour of endothelial cells on a type-I collagen matrix using histological and immunohistological methods. The endothelial cells were isolated from human umbilical cord veins and were identified as endothelial cells by staining with a panel of endothelial cell specific antibodies. After two passages cells were seeded in standard density on a type-I collagen matrix. After 1 and 7 days attachment, proliferation, differentiation and adhesion of the cells were analysed with specific markers. We could demonstrate that type-I collagen is an ideal matrix for endothelial cells concerning growth and maturation and that it could be used as a carrier matrix for different cell types during tissue engineering. Schlagwörter: endothelial cells, collagen, adhesion, proliferation, differentiation