Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is the third strain of coronavirus with a possible zoonotic origin, which has been labeled deadly since the beginning of the new millennium. Due to various factors affecting the morbidity and mortality of coronavirus disease 2019 (COVID-19) and its various clinical syndromes, in this study we examined the relationship between the ABO blood group and the severity of COVID-19 patients. In this cross-sectional study, the required information was obtained by studying all records of patients with COVID-19 admitted to Razi Hospital in Rasht from April to May 2020. Information in patients' records including age, gender, clinical signs, blood type, high-resolution computed tomography (HRCT) findings, and nasopharyngeal tests was collected. In total, 548 cases were studied; of which 305 patients were male and 243 patients were female. The mean and standard deviation of patients' age was 58.15 ± 0.7 years. PCR test was performed for 195 patients. ABO positive/negative blood group was not significantly associated with disease severity in patients with COVID-19. The results of the present study showed that gender, age, history of underlying disease, disease severity, and ABO blood group were not significantly associated with disease severity.
