The COVID-19 pandemic has created a global health crisis posing an unprecedented public health emergency. The number of deaths and people being infected were increasing daily throughout the globe. Aims & Objective: The primary aim of this study was to investigate association between mortality risk and elevated RDW at hospital admission and during hospitalization exists in patients with COVID-19. Material and Methods: Clinical data retrospectively analyse for all patients who tested positive for SARS-CoV-2 infection between Feb, 2021 and June, 2021. This cohort study will include adults diagnosed with SARSCoV-2 infection on RTPCR, with moderate to severe cases and admitted to multispeciality covid referral hospital. The study measured several variables. The patients’ demographic and clinical data that was measured included body mass index, age, and sex. Patients admitted to the hospital with laboratory-confirmed positive result for COVID by RTPCR assay of a nasopharyngeal swab sample. Significance levels were tested using Chi-square tests that provided comparisons between groups of patients who survived or perished from the disease. The Cox proportional hazards regression model was used to analyze inpatient COVID-19 mortalities of patients stratified by RDW levels, measured at their time of admission Results: The mean age of the subjects was 59 years with a standard deviation of 17 years. Out of 820, Number 427 patients (52.07%) were male. Male patients had a worse outcome with 61% of all fatalities. when mortality rates were stratified by age and RDW at admission of patient, it was established that normal RDW levels, 14.5% or lower, mortality levels were significantly lower. The lowest mortality levels were noted in younger age groups but significantly increased with increase in age. However, when the RDW levels were higher than normal at admission, the mortality levels increased fourfold as compared with similar age groups that had normal RDW levels. The findings indicate that increased RDW at admission increased mortality levels from 11.5% to 32%. This indicates that RDW would be used as a predictor of SARS-COV-2 severity. Conclusion: Elevated RDW levels at admission and increasing levels during hospitalization were associated with significantly higher mortality risk for patients with SARS-CoV-2 infection.