Objectives: ABO and Rhesus (Rh) blood group systems are the most clinically significant among the list of different identified blood groups. Prevalence of ABO and Rh blood groups over the entire Lebanese population was determined. Design and Methods: 103967 blood samples were typed for both ABO and Rh (antigen D) blood group antigens. Results: Upon considering the ABO but not RhD antigen, we identified the blood group O to be the most frequent (38%) and AB to be the least common (4%). Upon considering both ABO and RhD antigen, A RhD+ blood group was the most frequent (34%) whilst AB Rh- was the least common (0.4%). RhD+ blood groups were in the following order: A (33.86%)>O (33.09%)>B (17.79%)>AB (3.64%), while RhD- ones were: O (5.36%)>A (4.02)>B (1.81%)>AB (0.43%). Conclusions: Overall, our data determines the prevalence of ABO and RhD blood groups over the entire Lebanese population which is indispensable for blood banks and transfusion policies.