Since the end of 2019, Egypt and the whole world have been suffering from the Coronavirus Disease 2019 (COVID-19) pandemic, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). According to the World Health Organization (WHO), since the emergence of this new pandemic, there have been more than 97 million confirmed cases of COVID-19 patients and two million death globally; around 160 thousand of these cases are in Egypt. Recent clinical investigations found a high incidence of thrombotic complications in these patients, even with the standard anticoagulant thromboprophylaxis.Coronavirus disease 2019 (COVID-19) causes a hypercoagulable state. Among the pathological sequel of COVID-19 infection, is the presence of a micro-thrombi in the pulmonary circulation which was shown in several autopsy studies. This thrombosis is believed to contribute to gas exchange impairment among patients with COVID-19 infection. Some observational studies have shown anticoagulation benefits with reduced mortality, mainly in patients requiring mechanical ventilation. However, these findings remain uncertain and need to be validated in further studies. This study is performed to evaluate whether therapeutic anticoagulation could improve COVID-19 patients' clinical outcomes compared to prophylactic anticoagulation in terms of improving gas exchange, reducing the need to maintain mechanical ventilation, shortening hospital admission period and mortality rate as well as recovering D-dimmer levels to its normal values.