Despite the considerable advances in the diagnostic and therapeutic possibilities, the prognosis of epithelial tumors in the oral cavity is very poor. A knowledge of the prognostic factors at the beginning of treatment is therefore indispensable for determination of the appropriate therapy for the given patient. These factors may be linked to the patient (e.g. age, sex, general condition and immunological parameters) or to the tumor (localization, TNM stage, histological features, DNA content, or immunohistochemical and other parameters). A survey of the literature reveals that the TNM stage, the grade, the mode of invasion and the depth of the tumor are generally the most important factors influencing the fate of the patient. The prognosis primarily depends on the clinicopathological parameters, though even if they are known, it is not possible to screen out those patients who are at particular risk of a relapse. During the past 10 years, study of the DNA content, the proliferation markers and certain oncogenes has came into the focus of attention; great interest is also shown in the matrix metalloproteinases, which play key roles in the invasion and metastasis formation.