β-thalassemia the furthermost widespread hereditary hematological condition, is brought on by decreased or missing ß globin chain production, which results in hemolysis and impairs erythropoiesis. It affects millions of people worldwide, including those living in developed and developing nations. Aim of research is study the distribution and relationship of blood types with β-thalassemia, in addition we aim to investigate the relationship, affinity and genetic predisposition between blood types and β-thalassemia. The retrospective study was done in Iraq which including 200 patients of β-thalassemia were examined for blood types test and molecular analysis for determine the various mutations. Our results showed that β- thalassemia in female (51%) more than male (49%) and blood groups was showed statistically high significant with gender, in female predominant blood group was O +Ve followed by B +Ve while in male was A +Ve followed by O +Ve. In addition to age of patients appeared significant differences with β-thalassemia the high rate was in aged group betwe en (18-25 years). Different mutations were detected in this study: IVS 2.1[G>A] (30%) was predominant mutation in patients with blood group O +Ve (30%) followed by 25 % in A +Ve, IVS 1.110 [G>A] (17%), IVS 1.6 [T>C] was 12%, IVS 1.5 [G>C] 8%, in addition to other mutations. In our research may be found some relation between blood group and β-thalassemia, which appeared high percentage in female and in young people in patients with blood group O +Ve.