Fifty-three patients with invasive transitional cell carcinoma of the renal pelvis and ureter were studied for p53 protein overexpression by immunohistochemistry. Overexpression of p53 protein was observed in 19 patients (35.8%). There was a significant correlation between overexpression of p53 protein and histologic grade (p < 0.01). However, there was no correlation found between p53 immunoreactivity and pathologic stage. By univariate survival analysis, a significant difference in cumulative survival was observed between stage pT2 and stage pT3 or pT4 tumors (p < 0.05). The difference in survival between patients with p53-positive and negative tumors did not reach statistical significance (0.05 < p < 0.1). Multivariate analysis revealed that pathologic stage had an independent prognostic value (p < 0.05). The independent prognostic value of p53 protein overexpression did not quite reach statistical significance (p = 0.07). p53 protein nuclear overexpression appears to be a relatively weak prognostic indicator for patients with invasive transitional cell carcinoma of the renal pelvis and ureter.