Overexpression of histone demethylase PHF8 has been reported to function as an oncoprotein in many cancers; however, the implications of PHF8 involvement in laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC) remain unclear. This study aims to explore the expression of PHF8 and its clinical significance in LHSCC. Western blotting and immunohistochemistry were performed to evaluate PHF8 protein expression in fresh and archived LHSCC samples. Global expressions of H3K27 and H3K9 methylation were analyzed in a cell line with PHF8 siRNA treatment. In our study, PHF8 was upregulated in fresh LHSCC tissues. Immunohistochemical staining revealed that the expression of PHF8 was positively associated with T classification, clinical stage, primary tumor position and tumor relapse. Survival analysis demonstrated that high PHF8 expression was significantly associated with shorter overall survival and disease-free survival. Moreover, PHF8 regulates the levels of H3K9me2 and H3K27me2 in LHSCC. Taken together, PHF8 might be a novel prognostic marker for this disease.