A retrospective clinicopathological study was done of 136 T1 bladder cancer patients, mean follow-up 10 years. With interactive morphometry, mean nuclear area, mean standard deviation of nuclear area (SDNA) and the mean area of the 10 largest nuclei (NA10) were measured in biopsy specimens from primary tumours. Volume corrected mitotic index (M/V index) was estimated in the same sections. Histological grading was done according to WHO and clinical staging according to UICC. Progress in bladder cancer was observed in 26 cases. Progressing tumours had significantly higher M/V values (P = 0.0038) than tumours without progression. By chi 2 statistics NA10 (P = 0.0065) and high M/V index values (P = 0.0104) eventually metastasised. Nuclear area (P = 0.0025), NA10 (P = 0.0053), histological grade (P = 0.0071), NA (P = 0.0563) and M/V index (P = 0.0979) predicted bladder cancer-related survival, in that order. The recurrence rate or recurrence-free period were not related to histological indices. The results suggest the use of these morphometric features instead of histological grading in the prediction of T1 bladder tumours.