Purpose To explore whether the expression of nuclear factor-κB(NF-κB)is related to the expression of vimentin in thyroid tissues from Hashimoto's thyroiditis(HT) patients.Methods 28 formalin-fixed and paraffin-embedded HT specimens and 9 control specimens were collected.CK8,vimentin and NF-κB were detected by SP immunohistochemistry(IHC) staining and co-expression between them was analyzed on serial sections of the thyroid specimens.The immunoflurenscence(IF) double-staining assay and confocal laser scanning microscopy were conducted to detect the co-localization of CK8 and vimentin,and NF-κB and vimentin in cold ethanol-fixed,paraffin-embedded HT sections.Results The mean positive rates of vimentin in the two groups were 68.9%±39.87% and 22.4%±34.63% respectively.There was significant difference statistically(P=0.004).The positive rates of NF-κB in the HT group and the control group were 64.29%(18/28) and 11.11%(1/9) respectively,with a significant difference statistically(P=0.008).The expression of vimentin was closely related to that of NF-κB(r=0.662,P0.01).The IF double-staining assay showed that CK8 and vimentin,and vimentin and NF-κB co-existed in the cytoplasm of epithelial cells in the HT.Conclusion The higher expression of NF-κB is related to the increased expression of vimentin in HT patients,indicating that it plays an important role in epithelial-mesenchymal transformation of the diseased epithelial cells by mediating vimentin gene.