In vivo endothelial cell exploration in human pathology has been limited by the lack of a suitable procedure for quantification of endothelial molecule expression. The objective of the present study was the development of a precise, simple and rapid image analysis method to quantify dermis endothelial cells and associated molecules. Cutaneous tissue sections were labelled by immunoperoxidase procedure using a monoclonal anti-von Willebrand factor (vWF) antibody, which identifies endothelial cells. The image analysis programme was tested to quantify final reaction deposit (DAB) with reference to different anti-vWF antibody concentrations. The entire biopsy section was acquired, field by field. Analysis was restricted to three dermis zones geodesically defined from epidermis. Optical density and area measurements were performed in whole area and in positive areas. This work demonstrated the feasibility of endothelial cell study assisted by image analysis. Surface labelled by anti-vWF antibody at saturating concentration may be considered as an endothelial reference surface, and thus may be useful for future quantification of other endothelial molecules.