β-Thalassemia (β-thal) is characterized by the absent or reduced production of β-globin chains. The precise molecular lesion that causes decreased β-globin synthesis in β(+)-thal is difficult to predict when mutations occur in the locus control region (LCR), the promoter, the introns or 3' untranslated regions (3'UTRs). Among them, the role of the 3'UTR of β-globin gene in mRNA stability is poorly understood, mainly due to very few cases that have mutations in this region. So far, only three mutations have been reported in the 3'UTR of β-globin gene. Although, it is speculated that some of these reported mutations could be associated with mRNA stability, the precise molecular basis still remains unclear. We report here a novel mutation in the β-globin gene 3'UTR [+1,506 (A>C)] in a 31-year-old Japanese male with hematological parameters suggestive of heterozygous β-thal. Further functional studies on this novel mutation reported here, may help in understanding of the regulation and expression of the β-globin gene and its products.