The Fas/Fas ligand (FasL) pathway has been shown to be an important cellular pathway mediating apoptosis. In this study we investigated the expression of Fas and FasL and the rate of spontaneous apoptosis in 58 oral and oropharyngeal squamous cell carcinoma (SCC) by using immunohistochemical techniques. There was no correlation between Fas or FasL expression and clinicopathological factors. The expression of Fas in the tumor did not affect spontaneous apoptosis of the tumor cells. However, FasL expression was associated with IL-10 and granulocyte colony-stimulating factor expression in oral and oropharyngeal SCC. These results suggested that the Fas/FasL system is connected with the expression of various factors including cytokines in tumor cells.