SUMMARY: p53 alterations have been implicated in oral carcinogenesis process. Squamous cell carcinoma is the most common malignancy of the oral cavity, the tongue being the most frequent affected site. The aim of this study was to compare p53 immunoexpression in 43 samples of oral SCC from 5 different anatomical sites: tongue, floor of the mouth, alveolar ridge/gingiva, retromolar region and other regions of the oral cavity. Thirty-three lesions (76,8%) showed positivity for p53 (mean index of 48,37%). No statistically significant differences were found between p53 expression and the different oral sites analyzed. Similarly, no differences were found when comparing tongue lesions with the remaining sites. These results suggest that it might not exist any difference among oral cavity anatomical sites in relation to p53 immunoexpression. Moreover, mechanisms other than p53 alterations in squamous cell carcinomas of the tongue may be of relevance for the higher tumour aggressiveness found in this anatomical site.KEY WORDS: p53 protein; Immunohistochemistry; Oral squamous cell carcinoma (OSCC).