Paraffin embedded tissue from 249 transitional cell bladder cancers (TCC) was stained by an antibody against c-erbB-2 oncoprotein to evaluate its overexpression. The staining results were related to histopathological features and clinical follow-up data. 99/249 (39%) of tumours were positive for c-erbB-2 oncoprotein and 31/249 (12.5%) of them showed moderate or heavy staining. c-erbB-2 overexpression was related to pelvic lymph node involvement (P = 0.0355) and distant metastasis (P = 0.0058) at the time of diagnosis, whereas no significant relationship was found between T-category and c-erbB-2 oncoprotein overexpression. Expression of c-erbB-2 was related to high WHO grade (P = 0.0033), DNA aneuploidy (P = 0.0061), high S-phase fraction (P = 0.042), and several morphometric nuclear factors (P = 0.01-0.09). All the tumours with high levels of c-erbB-2 expression were tetraploid in flow cytometry (P < 0.0001). c-erbB-2 expression predicted recurrence-free survival in superficial tumours (P = 0.057) and in survival analysis moderate or intense expression of c-erbB-2 oncoprotein was related to decreased survival probability (P = 0.27). In multivariate survival analysis overexpression of c-erbB-2 had no independent prognostic value. The results show that immunohistochemical demonstration of c-erbB-2 oncoprotein overexpression in paraffin embedded archival material has no prognostic value over already established predictors in TCC.