Background: Coronavirus disease-2019 (COVID-19) has been associated with cardiovascular complications and coagulation disorders. Objectives: To explore the coagulopathy and endothelial dysfunction in COVID-19 patients. Methods: The study analyzed clinical and biological profiles of patients with suspected COVID-19 infection at admission, including hemostasis tests and quantification of circulating endothelial cells (CECs). Results: Among 96 consecutive COVID-19-suspected patients fulfilling criteria for hospitalization, 66 were tested positive for SARS-CoV-2. COVID-19-positive patients were more likely to present with fever (P =.02), cough (P =.03), and pneumonia at computed tomography (CT) scan (P =.002) at admission. Prevalence of D-dimer >500 ng/mL was higher in COVID-19-positive patients (74.2% versus 43.3%; P =.007). No sign of disseminated intravascular coagulation were identified. Adding D-dimers >500 ng/mL to gender and pneumonia at CT scan in receiver operating characteristic curve analysis significantly increased area under the curve for COVID-19 diagnosis. COVID-19-positive patients had significantly more CECs at admission (P =.008) than COVID-19-negative ones. COVID-19-positive patients treated with curative anticoagulant prior to admission had fewer CECs (P =.02) than those without. Interestingly, patients treated with curative anticoagulation and angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers had even fewer CECs (P =.007). Conclusion: Curative anticoagulation could prevent COVID-19-associated coagulopathy and endothelial lesion.