A retrospective follow-up (range 9.4-22 years, mean 13 years) study of 83 patients with grade I-III (WHO) bladder carcinomas was performed. Nuclear area (mean +/- SD 59.7 +/- 18.7 microns2) and the SD of nuclear area (mean +/- SD 19.7 +/- 13.4 microns2) were determined by using morphometric methods. The SD of nuclear area and histopathological grade exhibited a clearly significant relation, the relation between grade and nuclear area was weaker. The number of recurrences in the bladder and the recurrence-free period were not significantly related to histopathological grade, mean nuclear area or SD of nuclear area. The progress in nodal or metastatic stage could be predicted by histopathological grade, mean nuclear area and SD of the nuclear area. Prediction of crude survival, however, was not efficient. When only bladder cancer deaths were included in the analysis, histopathological grade (p less than 0.001), mean nuclear area (p = 0.011) and SD of the nuclear area (p = 0.001) showed a significant relation to survival. Grade II tumors could be divided into two prognostically different groups using nuclear area and SD of the nuclear area as classifiers. The results suggest that morphometric parameters are as good as histopathological grade in predicting long-term prognosis of bladder carcinomas, and better than the histopathological grade in predicting progress in nodal (N) or metastatic (M) stage.