In 1997, the U.I.C.C. (International Union against Cancer) modified the previous TNM stage grouping published in 1987. In the present study, TANIS and TNM '97 systems were compared in order to evaluate their prognostic ability. Data from 164 patients affected by primary squamous cell carcinoma cancers of the oral cavity (n=100) and oropharynx (n=64) were analyzed by means of survival analyses. Both systems showed a significant correlation with survival rate. TANIS yielded better results in association with the survival rate as compared with TNM '97.