COVID-19 caused by the SARS-CoV-2 virus is a new type of infection which has caused an enormous social and economic burden across the world. While most people will develop a mild-to-moderate form of the disease or even stay asymptomatic, a certain proportion will get critically ill. COVID-19 mortality risk is higher in elderly patients and in patients with cardiovascular diseases and diabetes. Molecular mechanisms which underlie these risks are not yet understood for COVID-19. Here I discuss a possible association of COVID-19 complications with von Willebrand factor (VWF) level and endothelial damage. VFW is an important prognostic marker of endothelial dysfunction and its level fluctuates depending on age. VWF level is also variable depending on sex and race. Importantly, chloroquine, a drug that showed potential efficacy for COVID-19 treatment, can influence VWF secretion and consequently its level and activity. I propose that VWF level and activity might be predictors of the COVID-19 morbidity and mortalit