Objective: β thalassemia and sickle cell disease are characterized by a chronic transfusion associated with chelation. Patients are exposed highs toxicity with iron overload. This manifests differently in these illnesses, in thalassemia by an increased of pro-oxidant molecules, reducing the activity of antioxidant system and endocrine disorders. For sickle cell inflammation is more marked. Our study aims to evaluate the status of oxidative in these illnesses carrying the mutation Codon 6 beta globin gene. Materials and Methods: We have studied in this work 14 individuals, including (5) healthy subjects, (6) β-thalassemia homozygotes their mutations were characterized in a later study and (3) sickle cell anemia, they were followed at the hematological department of the Beni-Messous Hospital in Algiers, Algeria. Molecular study consist to extract the DNA genomic of all subjects by “modified salting out” technique, amplifying β globin gene, characterize the mutation by RFLP ‘’ BSU 36I enzyme”. Biochemical study is aimed at analyzing the serum for all individuals to some stress markers (MDA and catalase), the evaluation of iron status [ferritin, serum iron, the total iron-binding capacity (TIBC)] main parameters involved in the complications of these diseases. Results: We find a higher serum iron in β-thalassemia compared to the control group by a factor 2 and that of sickle cell. The TIBC in β-thalassemia have the highest rate followed by those of sickle cell disease and controls. Ferritin, the best indicator of the amount of iron stores, β-thalassemia where iron overload is installed it is the highest. However it remains in the range of standards for sickle and controls. There was a significant rate of serum MDA “marker of lipid peroxidation” in β thalassemia compared to controls by a factor of 1.59, and catalase showed a nonsignificant decrease activity in sickle cell disease; however this decrease was significant in β-thalassemia, and reached a factor of 1.26. Conclusion: Free iron accumulation, is the source of the free radical OH° via the Fenton reaction, which alters the cell membranes in liver, heart and endocrine glands. The alterations produced of accelerated apoptosis and ineffective erythropoiesis. Our results confirm the role of stress and decreased antioxidant capacity appears to be a common feature of these two diseases. Vitamin deficiencies in patients with thalassemia were observed with a consequent worsening of alterations.