Despite improvement in the safety of blood products, SCD patients are at greater risk than the general population for hepatitis B infection and chronic liver disease, making hepatitis B immunization especially important for this population.Aim of this work is to evaluate and follow up the antibody response to hepatitis B vaccination after years of starting obligatory vaccination in patients with SCD.The study has been conducted on 58 child, 30 sickle cell patients, 10 thalassemia patients and 18 age matched normal children were included as a control group.Concerning the anti-HBs titer in SCD patients ranged between 5.6 to 500 IU/L (98.2 ± 30), while in patients ranged between 16 to 343 IU/L (93.4 ± 30) and in control group ranged between 10 to 523 (83.4 ± 28.1).40% of SCD patients showed an anti-HBs titer below 10 IU/L, while neither of the thalassemic patients nor the control group revealed such non protective titer.Achievement of a protective or non protective titer has no correlation with age, age at presentation, no. of blood transfusion/year, no. of crisis/year, sex, consanguinity or any of the laboratory data except for the age of first blood transfusion and positive family history.Booster doses of HBV vaccine in SCD patients are mandatory.