p53 gene mutations have been known to be highly related to the particular stage of transformation in various types of human cancers. This study was conducted to investigate the p53 mutations at the protein level by an immunohistochemical method using anti-p53 antibody, NCL-p53-DO-7. Twenty-five cancer specimens were obtained surgically from patients with squamous cell cancer of the skin at the Korea Cancer Center Hospital. The cancers were classified according to the possible etiology into two groups, burn scar originated and UV-related cancers. Overexpression of p53 protein was detected in ten (40%) out of 25 cases tested: six (40%) of 15 cases associated with burn scar and four (40%) of ten cases related to UV exposure. In all normal skin cells in specimens, p53 protein was not stained at all. The stages and histological grades were evaluated for their relationship with the overexpression of p53 protein. No significant difference was found between the overexpression of p53 protein and the stages or histological grades. These results demonstrating that 40% of skin cancers were positive for p53 overexpression suggest that the alterations of the p53 gene may play a role and the exact role of p53 gene in the development of squamous cell carcinoma of the skin will be studied.