The clinical presentation of COVID-19, varies from no symptoms to severe symptoms with complications like acute respiratory failure, acute respiratory distress syndrome, metabolic acidosis, coagulopathy, and septic shock. A full blood count is a routine, inexpensive and easy test that provides information about formed blood contents. Patients with severe COVID-19 disease present with increased leucocytosis, neutrophilia, lymphopenia, eosinopenia and thrombocytopenia than those with non-severe disease. Recently, reports on the feasibility of few new haematological parameters like, Neutrophil to Lymphocyte ratio (NLR) , Lymphocyte to Monocyte ratio (LMR) and Platelet to Lymphocyte ratio (PLR) in predicting prognosis in patients with SARS-CoV-2 infection have been published. The current study shows that these parameters may be a rapid, cost-effective, widely available, useful prognostic factor in the early screening of critical illness in patients with confirmed COVID-19. These parame