The first two patients with beta-thalassemia major in Turkey, were reported in 1941. However, the importance of beta-thalassemia as a health problem was brought to the attention of physicians only after 1950. In Turkey, the clinical and hematological pictures of beta thalassemia were found to be mostly heterogenous. Hematological data of patients with mild disease (beta-thalassemia intermedia) severe beta-thalassemia (beta-thalassemia major) and heterozygotes indicate that patients can be grouped according to the content of Hb F, Hb A2 and red cell indices.