Superficial transitional cell carcinoma of the bladder (STCCB) is a heterogeneous group of neoplasias with an unpredictable clinical course. In recent years many techniques have been used in order to predict the behaviour of these tumours at individual patient level. The aim of this study was to investigate in imprints from tumour biopsies the DNA ploidy and p53 protein expression in a group of 80 STCCB (pTa-pT1) patients in relation to histological grade and recurrence status. The DNA content was studied in Feulgen-stained imprints by the image analysis technique using a SAMBA 2005 analyser. In order to investigate p53 protein expression an avidin-extravidin immunocytochemical technique was used. According to our measurements a strong correlation was observed between recurrence status and DNA ploidy status (P < 0.001). No statistical difference was found in DNA ploidy status and grade of malignancy (P = 0.68). A statistically significant difference was found in p53 protein expression between recurrent and nonrecurrent tumours (P < 0.001). No statistically significant difference was found among tumours of grade I, grade II and grade III (P = 0.42). These results could provide useful information on the potential behaviour of STCCB.