Beta-thalassemia is the most prevalent monogenic and inherited blood disorder worldwide with approximately 317,000 affected individuals each year. In Egypt, β-thalassemia is the most common genetically-determined, chronic, hemolytic anemia. It had been calculated in Egypt that one thousand children out of 1.5 million live births are born annually with thalassemia major and its carrier rate has been estimated at 9–10.2%. Thalassemia exhibit a wide spectrum of phenotypes. Depending on the clinical severity. Thalassemia is generally divided into three groups: carriers of Thalassemia minor/trait are often asymptomatic and do not need any treatment, those with Thalassemia intermedia have moderate anemia, and occasionally require red blood cell transfusion and Thalassemia major. β-Thalassemia is caused by reduced (β+) or absent (β0) synthesis of the β-globin chains of hemoglobin. Thalassemia exhibit a wide spectrum of phenotypes. Depending on the clinical severity. It is generally divided into three groups: carriers of Thalassemia minor/trait are often asymptomatic and do not need any treatment, those with Thalassemia intermedia have moderate anemia, and occasionally require red blood cell transfusion and Thalassemia major. Thalassemia major patients need a regular blood transfusion and iron chelation therapy which leads to poor life quality for them and a massive financial burden on the clinical care system. Therefore prevention policies are greatly needed, they include carrier screening, gene counseling and prenatal diagnosis.For reliable screening test, different blood count parameters are investigated and several mathematical formulae are developed.