Aim: Although antithrombotic drugs have a routine place in the treatment of severe COVID-19 patients, it is not yet known whether the use of antithrombotic drugs for any reason before exposure to infection has an effect on the prognosis and clinical course of the disease. The aim of this study is to determine whether the use of antithrombotic drugs before exposure to SARS COV-2 has an effect on the clinical course and mortality of the disease. Material and Methods: All patients who were admitted to our hospital's COVID-19 outpatient clinic, diagnosed with COVID-19, confirmed by RT-qPCR test results, and diagnosed with COVID-19 pneumonia with a lung imaging were included in the study. Anamnesis information of patients with Covid-19 pneumonia, length of stay in hospital and intensive care unit were obtained and recorded in the hospital registry system. Clinical outcomes of all patients were recorded as survival or exitus. Results: The total number of patients with a positive PCR test result and viral pneumonia was 415. The mean age of the patients was 53 ±19 and 234 (56%) were male. While 168 (40%) of 415 patients were using at least one type of antithrombotic drug, 247 (60%) were not using any antithrombotic drug. While the mortality rate was 4.5% in 168 patients who used antithrombotic drugs before COVID-19, the mortality rate was 12.5% in 247 patients who did not use antithrombotic drugs (p= 0.008). While the rate of hospitalization in the intensive care unit was 10.1% in 168 patients who used antithrombotic drugs, the rate of intensive care was 13.7% in 247 patients who did not use antithrombotic drugs (p= 0.31). Conclusion: Antithrombotic therapy in early disease, especially in outpatients, may prevent coagulopathy and endothelial-associated disease, but administration of antithrombotic therapy too late during the thrombo-inflammatory phase may not provide the necessary protective effect. This hypothesis needs to be tested in appropriate prospective randomized trials.