Despite thromboprophylaxis, patients with coronavirus-19 disease (COVID-19) exhibit hypercoagulability and higher venous thromboembolic risk, although its real incidence is still unknown. The aim of the study was to evaluate the incidence of venous thromboembolism in COVID-19 patients admitted to both intensive care unit and medical ward. Consecutive patients admitted for COVID-19 to medical ward and intensive care unit at Padua University Hospital, all receiving thromboprophylaxis, underwent systematic ultrasonography of internal jugular, upper and lower limbs veins every 7(±1) days after the admission; and if negative, once-weekly until discharge or death. In case of suspected pulmonary embolism, a multi-detector computed tomographic angiography was performed. The primary outcome was the proportion of any deep-vein thrombosis and symptomatic pulmonary embolism in both groups. An extended blood coagulative test was performed as well. From March 4 to April 30, 2020 a total of 85 patients were investigated, 44 (52%) in medical ward and 41 (48%) in intensive care unit. Despite thromboprophylaxis, venous thromboembolism occurred in 12 medical ward (27.3%) and 31 intensive care unit patients (75.6%) with an Odds Ratio of 9.3 (95%CI, 3.5 to 24.5;p<0.001). Multiple-site deep-vein thrombosis occurred in 55.6% of patients (95%CI, 39.6 to 70.5). Increased D-Dimer levels significantly correlated with venous thromboembolism (p=0.001) and death (p=0.015). Summarizing, COVID-19 patients admitted to medical ward or intensive care unit showed a high frequency of venous thromboembolism, despite standard- or high-dose thromboprophylaxis. Whether thrombosis, particularly asymptomatic events, may play a role in the morbidity and mortality of COVID-19 patients remain to be clarified.This article is protected by copyright. All rights reserved.