Aim. To investigate plasma hemostasis in patients with different levels of COVID-19 severity. Materials and methods. The study included 46 patients with confirmed COVID-19, who were stratified into four groups based on disease severity as mild (1), moderate (2), severe (3), and critically severe (4). Laboratory investigations included APTT, Quick's prothrombin time, concentration of D-dimer, fibrinogen, ATIII, and platelet count. Results. D-dimer concentration >450 ng/ml was found in 100% of patients increasing from 973 (545–1635) ng/ml in group 1 to 13513 (7627–22512) ng/ml in group 4 (p