Background: A considerably marked increase in inflammation markers has been observed in patients with COVID-19 disease, this proinflammatory state can cause endothelial dysfunction, ultrastructural features of endothelial cell distribution and SARS-COV2 visible within the cell have been described in patients who died from COVID-19. Aim: to assess the possible involvement of ADAMTS13 in the coagulopathy associated with COVID-19. Methods: This retrospective study conducted on 66 cases were divided into 3 groups; Group (I): (22) moderately diseased patient at isolation room. Group (II): (22) severe diseased patient in intensive care. Group (III): (22) apparently healthy individuals of mating age and sex with negative PCR for COVID. Results: there was a statistically significant increase in CRP, bilirubin among severe cases compared to non-severe. There was a statistical significance difference between the studied groups in ADAMTS 13. Post hoc test showed that there was a statistical significance decrease in ADAMTS 13 among severe cases compared to non-severe and control and among non-severe cases compared to control. ADAMTS 13 at cut off <1199.4 ng/ml had sensitivity 90%, specificity 90% and accuracy 90% in diagnosis of COVID-19. Moreover, ADAMTS 13 at cut off <575.49ng/ml had sensitivity 75%, specificity 65% and accuracy 70% in diagnosis of severe COVID-19 among cases groups. Conclusion: Decreased ADAMTS13 associated with unfavorable outcomes of patients with COVID-19.