The thalassemias are a group of autosomal recessive genetic disorders of hemoglobin synthesis. The thalassemias are classified into two main varieties, α- and β-, depending on which of the adult globin chain is produced in reduced amounts. The β-thalassemia is the homozygous and heterozygous state, and common in the Mediterranean region. Homozygous β-thalassemia is usually associated with severe anemia. β-Thalassemia minor, the heterozygous state, is characterized by hypochromia, microcytosis and an elevated of HgA₂. No treatment is required for thalassemia minor, but it is important to exclude iron deficiency anemia and postpartum genetic counseling. Recently, β-thalassemia minor keeps rising steadily in Korea due to the increase in international marriges. Recently we have experienced a vaginal delivery in a β-thalassemia minor Vietnam woman associated with mild anemia. We describe this case with a brief review of the literature.