Emerging evidences prove that the ongoing pandemic of coronavirus disease 2019 (COVID-19) is strictly linked to coagulopathy even if pneumonia appears as the major clinical manifestation. The exact incidence of thromboembolic events is largely unknown, so that a relative significant number of studies have been performed in order to explore thrombotic risk in COVID-19 patients. Cytokine storm, mediated by pro-inflammatory interleukins, tumor necrosis factor \alpha and elevated acute phase reactants, is primarily responsible for COVID-19-associated hypercoagulopathy. Also comorbidities, promoting endothelial dysfunction, contribute to a higher thromboembolic risk. In this review we aim to investigate epidemiology and clarify the pathophysiological pathways underlying hypercoagulability in COVID-19 patients, providing indications on the prevention of thromboembolic events in COVID-19. Furthermore we aim to reassume the pathophysiological paths involved in COVID-19 infection.