Background:The pathogenesis of hypercoagulability in COVID-19 patients is complex and not fully understood. Rotational thromboelastometry (ROTEM®) is a viscoelastic method that allows the definition of a patient’s hemostatic profile. This study aimed to assess the relationship between ROTEM®parameters, the profile of inflammatory cytokines, and clinical outcomes in COVID-19 patients.Methods:A total of 63 participants (n= 29 symptomatic non-ICU COVID-19 patients, andn= 34 healthy controls) were prospectively included in the study. We assessed the relationship between the parameters of three ROTEM®tests (NATEM®, EXTEM®, and FIBTEM®) and levels of CRP, interleukin-8, interleukin-1β, interleukin-6, interleukin-10, tumor necrosis factor, interleukin 12p70, and clinical outcomes.Results:ROTEM®indicated hypercoagulability in COVID-19 patients in all the tests performed. The levels of all inflammatory cytokines were significantly higher in COVID-19 patients. NATEM more frequently detected hypercoagulability in COVID-19 patients compared to EXTEM. The strongest correlations with inflammatory biomarkers and CT severity score were with FIBTEM parameters. The elevated maximum clot elasticity (MCE) in FIBTEM was the strongest predictor of poor outcomes.Conclusions:Increased FIBTEM MCE may be associated with greater severity of COVID-19. Non-activated ROTEM (NATEM test) seems to be more valuable for detecting hypercoagulability in COVID-19 patients compared to the tissue factor activated test (EXTEM).