In the bladder cancer the most important prognostic factors are the stage, the grade, the presence or absence of lymph nodal metastasis, the response to therapy with B. C. G. etc.... In any case, even in the context of the same clinical stage, it is not possible to correctly evaluate the evolution of the disease. The Author did a literature revision and got a personal contribution about the effective utility of same biological prognostic factors. In a study about superficial bladder tumor using monoclonal antibody MIB-1 (Ki-67) a correlation between proliferation index (P.I.) and grade was noted. In particular the presence of a P.I. above 40% correlated with greater precocity and frequency of recurrences. A similar study showed that the expression of protein p21 correlated with a greater precociousness and with recurrence frequency. In conclusion, we have also carried out an evaluative study on the expression of oncosuppressor gene p53. In superficial bladder cancer this study showed up a correlation between the expression of protein p53 and a greater precociousness and frequency of recurrences.