Mutant p53 protein overexpression is generally associated with poorly differentiated invasive bladder tumors. The survival in such cases is also expected to be poor. The objective of the present study was to determine whether immunohistochemical staining for p53 was predictive of lymph node metastases in early muscle invasive transitional cell bladder cancer. Immunohistochemical staining for mutant p53 was performed on formalin fixed transurethral resection specimens of 31 patients who underwent radical cystectomy. Eleven tumors were grade II and 20 tumors were grade III. There were 16 stage T2 and 15 stage T3a tumors. Staining with p53 was categorised as positive if distinct nuclear staining was observed in > or = 20% of the cells. Results were compared according to grade, stage (T2 versus T3a) and lymph node metastases. Seventeen tumors (55%) were positive for mutant p53. Eleven cases had lymph node metastases which could not be assessed preoperatively. The distribution of p53 positive rate between grade II and grade III cases, and T2 and T3a tumors was not different. All the 11 patients with lymph node metastases had positive tumors for p53. We assume that p53 positive rate can be used to distinguish high risk patients for lymph node metastasis. Patients with stage T2 or T3a and p53 positive bladder cancer should be considered for early aggressive treatment options.