This study was carried on 28 sickle cell anemia (HbSS) patients and 10 age and sex matched normal individuals as a control group. The patients were attending the pediatric hematology clinic of children hospital, Cairo University. In this study it was concluded that CD36 has a critical role in pathogenesis of vaso- occlusion that causes acute painful sickle cell crisis. Also it was concluded that hydroxyurea therapy not only induces HbF production and improve hematological parameters in SCA patients but also decreases the level of RBCs adhesion markers as CD36.