Background: β-Thalassemia is considered one of the common hemoglobin disorders in the Arabian Peninsula. Red blood cell (RBC) transfusion is a crucial component of the management of transfusion-dependent β-Thalassemia patients. Patients with Thalassemia Intermedia (TI), also known as non-transfusion dependent β thalassemia, have a wide clinical presentation and variable transfusion dependence. Rates of RBC alloimmunization and its risk factors in transfusion-dependent β thalassemia patients varied between different reports. Risk of alloimmunization is higher in TI patients