Involvement of the CXCR4-CXCL12 axis in the metastasis of many cancers including breast and prostate cancers has been reported. Objective: To assess whether the CXCR4-CXCL12 axis plays a role in the invasion of head and neck cancer cells. Methods: Six head and neck cancer cell lines namely HN4, HN12, HN18, HN17, HN30 and HN31 were used in this study. HN4, HN18 and HN30 were primary cancer cell lines whereas HN12, HN17 and HN 31 were metastatic cell lines. We phenotyped the cancer cell lines for expression of CXCR4, using fluorescence immunostaining. RT-PCR and Western blot were used to determine the levels of CXCR4 mRNA and CXCR4 protein in the cancer cell lines, respectively. Effect of CXCL12 and anti-human CXCR4 antibody on chemoinvasion of the cancer cells was performed using the Boyden chamber assay. Results: CXCR4 protein was expressed at the surfaces of 6 head and neck cancer cell lines. RT-PCR and Western blot demonstrated the expression of CXCR4 gene and protein in all cancer cell lines, respectively. CXCL12 significantly increased the invasion of cancer cell lines derived from the primary site (HN4 and HN30) except HN18 compared to that of cancer cell lines derived from the metastatic site (HN12 and HN31) (p <0.05). However, there was no correlation between the expression of CXCR4 and their invasive ability. Blocking of CXCR4 receptors with anti-human CXCR4 antibody could inhibit the invasion of all cancer cell lines except HN12. Conclusion: Our results suggest that CXCL12-CXCR4 signal has an important role in the invasion of head and neck cancer cells.