BACKGROUND: The number of patients diagnosed with hereditary hemolytic anemia (HHA) has increased since the advent of novel diagnostic techniques that accurately identify this disorder. Here, we report data from a survey on the prevalence and characteristics of patients diagnosed with HHA in Korea from 2007 to 2011. METHODS: Information on patients diagnosed with HHA in Korea and their clinical and laboratory results were collected using a survey questionnaire. Globin gene and red blood cell (RBC) enzyme analyses were performed. In addition, we analyzed data collected by pediatricians. RESULTS: In total, 195 cases of HHA were identified. Etiologies identified for HHA were RBC membranopathies, hemoglobinopathies, and RBC enzymopathies, which accounted for 127 (64%), 39 (19.9%), and 26 (13.3%) cases, respectively. Of the 39 patients with hemoglobinopathies, 26 were confirmed by globin gene analysis, including 20 patients with beta-thalassemia minor, 5 patients with alpha-thalassemia minor, and 1 patient with unstable hemoglobin disease. CONCLUSION: The number of patients diagnosed with hemoglobinopathies and RBC enzymopathies has increased considerably since the previous survey on HHA in Korea, dated from 1997 to 2006. This is likely the result of improved diagnostic techniques. Nevertheless, there is still a need for more sensitive diagnostic tests utilizing flow cytometry and for better standardization of test results to improve the accuracy of diagnosis of RBC membranopathies in Korea. Additionally, more accurate assays for the identification of RBC enzymopathies are warranted.