Von Willebrand factor (VWf) is a plasma protein that performs two main functions in hemostasis, it mediates platelet adhesion to the injured vessel wall, and it carries and protects coagulation factor VIII. It is synthesized in endothelial cells and megakaryocytes. New roles for Von Willebrand factor, especially in inflammatory processes, have recently been suggested. The aim of this study is to evaluate the role of Von Willebrand factor in different collagen vascular disorders as a marker of activity and to study the relation between VWf and vasculitic manifestations in different collagen vascular disorders. The results showed a significant increase in the VWf level in patients group compared to control group. It was also found that its level increases with the disease activity. From the study it is concluded that elevated levels of this protein are most likely a reflection of the existence of ongoing vascular damage; It can be particularly helpful in assessing the degree of systemic involvement in patients who present with cutaneous vasculitis as well as in quantifying disease activity in patients with the severe vasculitis.