Abstract: BACKGROUND AND AIM: Coronavirus Disease 2019 (COVID-19) infection is associated with an increased incidence of thromboembolic events. This study aimed to evaluate the frequency of in-hospital thromboembolic events in patients with COVID-19 and investigate the impact of blood parameters, measured at the time of diagnosis, on the development of thromboembolic events. METHODS: Demographic data, the frequency of thromboembolic events, and blood parameters at the time of diagnosis were recorded for all patients. RESULTS: A total of 2,323 patients, including 1,136 women (48.9%) and 1,187 men (51.1%) were included in the study. Thromboembolic events occurred in 103 (4.4%) patients during hospitalization. Deep vein thrombosis (DVT) was observed in four patients (0.2%), pulmonary thromboembolism (PTE) in three patients (0.15%), peripheral arterial disease in four patients (0.2%), cerebrovascular events in 17 patients (0.7%), mesenteric ischemia in one patient (0.05%), and myocardial infarction (MI) in 74 patients (3.2%). The frequency of thromboembolic events was significantly higher in patients with hypertension (HT) (p=0.03), heart failure (p=0.023), chronic kidney disease (p=0.017), and chronic obstructive pulmonary disease (COPD) (p=0.035) compared to those without these conditions. Patients with thromboembolic events were significantly older than those without such events (p=0.003). Among laboratory parameters, hemoglobin levels were significantly lower (p=0.002), and mean platelet volume (MPV) was significantly higher (p=0.009) in patients with thromboembolic events. Multiple regression analysis identified age (odds ratio [OR]: 1.014, 95% confidence interval [CI]: 1.001–1.027; p=0.032), hemoglobin levels (OR: 0.906, 95% CI: 0.824–0.997; p=0.043), and MPV (OR: 1.197, 95% CI: 1.030–1.391; p=0.019) as risk factors for thromboembolic events. CONCLUSIONS: Advanced age is a risk factor for thromboembolic events in patients with COVID-19. It is believed that hemoglobin levels and MPV at the time of hospital admission may also contribute to predicting thromboembolic events.