Growing reports on the impact of ABO blood types on COVID-19 contraction and severity are conflicting. This disagreement has been attributed to the failure in considering the basic epidemiologic concepts that prevent bias in such studies. In this work, we examined this hypothesis in a Tunisian group of healthcare professionals while respecting the basic epidemiologic principles to the maximum extent. 108 COVID-19-recovered unrelated patients, originating from 19 Tunisian governorates, were enrolled in this study. ABO blood typing for the recruited participants was performed according to established routine methods using a hemagglutination test. Reverse blood grouping (Serum Grouping) was performed, using known A and B red cells types, to confirm ABO blood group based on the presence or absence of anti-A and anti-B in the participant’s serum. Results show that the ABO type distribution in the group of COVID-19-recovered patients adjusts to the national Tunisian ABO spectrum. Furthermore, the analysis revealed that there is no link between the ABO blood types and COVID-19 severe outcomes namely the need for oxygen therapy and ICU admission. However, results show that carrying the B blood group could constitute a possible protective factor against chest pain (tightness) during the COVID-19 infection and men who produce anti-B antibodies could be protected against cough during the COVID-19 episode. Overall, this study shows that there is no impact of ABO blood types on either COVID-19 contraction or COVID-19 severe outcomes in the Tunisian group of healthcare professionals. Thus, larger international collaborative studies are required to further elucidate the link between this blood system and the COVID-19 disease, particularly in diverse ethnic groups.