Introduction: Since the onset of the SARS-CoV-2 pandemic in March 2019, scientists have been trying first to define the virus, the disease and even the factors that exacerbate the situation. Questions have arisen about the relationship between the patient's blood type, rhesus and the development of a COVID-19 infection. The purpose of this study is to determine whether or not there is a correlation between blood types, rhesus and COVID-19 disease, as well as its severity. Material and methods: We conducted a retrospective study of 7 months from August 2021 to February 2022, involving 59 patients with 33 male and 26 female subjects suspected of being infected with COVID-19, between the ages of 14 and 90. These patients were recruited from the Pasteur Institute "Oran Annex" and the Local Public Health Facility (EPSP BENI SAF). RT-qPCR techniques and blood grouping were used to determine the blood type of patients and whether or not they were infected with the SARS-CoV-2 virus. Patient information was retrieved from both facilities from medical records. Results: According to our results, 83% of patients tested positive for SARS-CoV-2 and 17% tested negative. The proportion of the O-group among those infected with SARS-CoV-2 (66%) was lower than in healthy patients (70%), while the proportion of the A-group (20%) was higher in negative patients than in positive patients (17%). The percentage of blood type B was identical in the affected and healthy groups (10%), while the AB group was present in affected patients (7%) and was completely absent in healthy patients. The p-value was 1 and this indicates that the link between blood type and COVID-19 infection is not significant. Conclusions: In light of our findings, there is a correlation between rhesus and the age of patients during the development of COVID-19 infection.