Introduction: The coronavirus disease 2019 (COVID-19) is caused by the virus SARS-CoV-2 and is declared as a global pan demic by the World Health Organization (WHO). Recently, many western and Chinese studies have done, but there is a need for research to evaluate the pattern of the haematological parameters of COVID-19 patients in the Indian population. Objective: The objective is to study the haematological parameters which include haemoglobin, Platelet count, Total leucocyte count, differential count, Neutrophil: Lymphocyte ratio (NLR), Platelet: Lymphocyte ratio (PLR) and Peripheral smear findings and to observe the correlation between various parameters and establish a pattern in Intensive care unit (ICU) and Non-ICU set-up in the Indian scenario. Methods: A retrospective study carried out on 150 COVID-19 patients admitted in June and July 2020 in a tertiary care hospital, Navi Mumbai, India. The haematological parameters of both Non-ICU and ICU patients were studied and compared for statisti cal analysis. Results: We observed lymphopenia, eosinopenia, neutrophilia, leucocytosis and decline of haemoglobin in COVID-19 con firmed cases. These parameters showed significant aggravation in critically-ill ICU patients as compared to the non-ICU group. Increased NLR identified as an important risk factor of severe illness. Although PLR did not show any significant difference. Morphology of leucocytes showed reactive changes. Conclusion: Real-time Polymerase chain reaction (RT-PCR), the confirmatory diagnostic test of COVID-19 is time-consuming and less accessible. Therefore, for initial diagnosis, severity assessment and ICU requirement, these haematological param eters are valuable.