Objective: Tumor stage, histological pattern, cell type, diameter and cell ploidy are the factor that have been proposed for predicting the prognosis of renal cell carcinoma (RCC). There isa wide variation in the reported incidence of p53 mutation in RCC, and its prognostic significance for this tumor is unknown. We investigated the prognostic value of p53 mutations among other prognostic factors. Patients and Method: We evaluated the stages, tumor diameters, histological grades, cellular patterns and the presence of mutant p53 protein in 50 cases of RCC. The survival function of each parameter was estimated by Kaplan-Meier and log-rank tests, and the significance of each para meter on survival was evaluated by logistic regression analysis. Results: The p53 mutation incidence was 20% in the RCC cases included in the study (n = 50). The survival rates of stages pT(2), pT(3) and pT(2-3)N+ were 87.8, 61.0 and 0%, respectively (p = 0.0462). The survival analysis of grade 1-2 and grade 3-4 tumors revealed 92.3 and 51.5% survival rates, respectively (p = 0.002). The survival rates of mutant p53+ and mutant p53- cases were 33.3 and 84.2%, respectively (p = 0.0027). The logistic regression test analysis demon strated that tumor grade, tumor stage and mutant p53 positivity status were the most significant prognostic factors (p < 0.03). The survival rates of mutant p53+ and p53- cases at stages pT(2), pT(3) and PT2-3N+ were 66.67 versus 91.48%, 33.3 versus 71.43% and 0 versus 100%, respectively(p = 0.0392). A similar finding was present at each stage for cellular grades (p = 0.0093). The survival rates of mutant p53+ and p53- cases for grades 3 and 4 were 33.33 and 74.48%, respectively (p = 0.2731). Conclusion: Our results suggested that many parameters can affect survial of RCC cases, but among these, tumor grade, tumor stage and p53 mutation status are the most important prognostic factors, but p53 mutation status and cellular grade can afford additional prognostic information at each stage. Copyright (C) 2001 S. Karger AG,Basel.