Sickle cell disease is characterized by the presence of intra-erythrocyte hemoglobin S, a tetramer composed of mutated (βS) beta globin (β) chains, in which the glutamic acid is replaced by a valine. This modification causes 'the formation of an HbS polymer that interacts with the erythrocyte membrane and deforms the red blood cells when the oxygen pressure is reduced. This process is known as sickling and it causes vaso-occlusive crises in the venous capillary. The obstruction of the blood vessels produces episodes of pain, hemolytic anemia, organs damage and early mortality. Chronic blood transfusions in individuals with sickle cell disease improve quality of life, decrease the symptoms of anemia, reduce the amount of circulating HbS and improve oxygenation capacity. Nevertheless, a recognized complication of transfusion is the alloimmunization against erythrocyte antigens, which may lead to hemolytic transfusion reaction. Prophylactic phenotyping is the method of prevention against alloimmunization in patients with sickle cell disease. However, these strategies are not effective since studies have shown that alloimmunizations against antigens of the Rh and Kell systems continue to occur in patients with sickle cell disease, despite transfusions were performed with compatible phenotype. This study genotyped the Rh (C/c and E/e) and Kell (K/k) antigens of 77 sickle cell disease patients and these results were compared to the erythrocyte phenotype. The alloimmunization rate was 36.4% and the specificity of the antibodies identified was mainly against the Rh system (55.17%); anti-Kell was found in only 5 patients (8.62%). There were 17 discrepancies between genotype and phenotype. As a result of these evaluations, a personal card containing information about the phenotype deduced from the genotype was made in order to be taken by the patients to their appointments at the public health network outside Federal District. Furthermore, this personal card will assist in the choice of compatible blood component.