question: AIM: To evaluate the burden and predictors of thromboembolic complications in a large real-life cohort of hospitalized patients with established coronavirus disease 2019 (COVID-19). METHODS: We retrospectively reviewed the records of 4014 consecutive adult patients admitted to a tertiary-level institution because of COVID-19 from March 2020 to March 2021 for the presence of venous and arterial thrombotic events. RESULTS: Venous-thromboembolic (VTE) events were present in 5.3% and arterial thrombotic events in 5.8% patients. The majority of arterial thromboses occurred before or on the day of admission, while the majority of VTE events occurred during hospitalization. The majority of both types of events occurred before intensive care unit (ICU) admission, although both types of events were associated with a higher need for ICU use and prolonged immobilization. In multivariate logistic regression, VTE events were independently associated with metastatic malignancy, known thrombophilia, lower mean corpuscular hemoglobin concentration, higher D-dimer, lower lactate dehydrogenase, longer duration of disease on admission, bilateral pneumonia, longer duration of hospitalization, and immobilization for at least one day. Arterial thromboses were independently associated with less severe COVID-19, higher Charlson comorbidity index, coronary artery disease, peripheral artery disease, history of cerebrovascular insult, aspirin use, lower C reactive protein, better functional status on admission, ICU use, immobilization for at least one day, absence of hyperlipoproteinemia, and absence of metastatic malignancy. CONCLUSION: Among hospitalized COVID-19 patients, venous and arterial thromboses differ in timing of presentation, association with COVID-19 severity, and other clinical characteristics.