ObjectiveTo investigate the expression and clinical significance of Raf1 kinase inhibitor protein (RKIP) in hypopharyngeal carcinoma.MethodsImmunohistochemistry was used to detect the expression of RKIP in 46 specimens of hypopharyngeal carcinoma and 13 of paracarcinoma squamous epithelium. All the results were analyzed with chisquare test and Wilcoxon test.ResultsThe expression of RKIP in the hypopharyngeal carcinoma was lower than that in the paracarcinoma squamous epithelium, and the difference was statistically significant (P=0.034).The positive expression rate of RKIP in carcinoma specimens with lymphatic metastasis was lower than that in those without lymphatic metastasis, and the difference was also significant (P=0.020).The positive expression rate of RKIP gradually declined from well differentiation to poor differentiation with statistically significant difference (P=0.005).ConclusionsThe differentiation degree of hypopharyngeal carcinoma is associated with the expression of RKIP. And the lymphatic metastasis of hypopharyngeal carcinoma is associated with expression deficiency or down regulation of RKIP.