This article summarize molecular-genetic basis of hemoglobinopathies, their classification and phenotypic manifestations. The description of individual subgroups is supplemented with a case reports of patients diagnosed in the Czech population. This paper provides an overview of 14 types of α-thalassemic mutations, 34 β-thalassemic alleles, 4 δβ-thalassemic alleles and 22 hemoglobin variants identified in the Czech population in 876 persons from 579 families. In more detail are described hemoglobinopathies, that have been diagnosed and described as novel: β-thalassemic mutation CD 38/39 (-C); Hb Olomouc; Hb Hana; Hb Hradec Kralove and 18.3 kb deletion downstream of α-globin cluster leading to a new mechanism of α-thalassemia-2. The fact that until the end of 2017 hemoglobinopathies were diagnosed in nearly 900 patients shows that they are not rare in the Czech Republic. This brings increased demands for their diagnostics, including prenatal diagnosis. Key words: hemoglobinopathies - hemoglobinopathy with high affinity to oxygen - sickle cell anemia - thalassemia - thalassemic hemoglobinopathy - unstable hemoglobins.