The hereditary hemolytic anemia (HHA) can be classified into three types according to the pathogenesis: RBC membrane defects, hemoglobinopathies, and RBC enzymopathies. Clinical characteristics of these three types of HHA are presented briefly in this paper. In Korea, HHA due to RBC membrane defect such as hereditary spherocytosis had been relatively well recognized, while HHA due to hemoglobinopathies and RBC enzymopathies had been considered rare. However, with the recent development of molecular testing, β thalassemia, G6PD and pyruvate kinase deficiency have been reported with identification of disease-causing mutations. If a patient with microcytic hypochromic anemia shows unproportionally low MCV or MCH or refractory to iron therapy, hemoglobin electrophoresis and gene study for thalassemia or other unstable hemoglobinopathies are needed. It should be noted that the recent population migration to Korea from the regions where hemoglobinopathies or enzymopathies are prevalent warrants considering a broad spectrum of etiologies for the diagnosis of HHA.