Our objective was to investigate the association between ABO Blood groups and the severity of COVID-19 and clinicopathological parameters.<h4>Methods</h4>An analytical cross-sectional study was conducted across three locations of Ziauddin University Hospital, including COVID-19 outpatient departments (OPDs), wards, and intensive care units (ICUs) from May 2020 to December 2020.The study utilized a non-probability convenient sampling technique with a sample size of 120 PCR-positive adult patients, as calculated by OpenEpi with a 95% confidence interval. The gene discussed is ABO; the disease is COVID-19.