Mutation and/or deletion of p53 tumor suppressor gene is one of the most common genetic abnormalities in diverse human cancers. The wild-type p53 gene participates in suppressing cell transformation while the mutant forms have tumorigenic potential. The wild-type p53 with a relatiely short half-life is found in all normal cell types with very low concentration and is undetectable by standard immunohistochemical staining. The mutant-forms with their prolonged half-life accumulate to much higher concentatrations in cells and can be detected by immunohisochemical staining. We evaluated p53 expression by immunohisochemical staining with anti-p53 monoclonal antibody. DO-1(Oncogene Science, Uniondale, NY) in 48 paraffin-embedded tissues of head and neck squamous cell carcinomas and investigated the relationship between p53 expression and clinicopathological status. Eighteen(38%) out of 48 cases showed p53 hyperexpression, however there was no singificant correlation between p53 expression and clinicopathological parameters such as tumor staging lymph node status, and tumor differentiation grade.