The identification of new prognostic parameters in Superficial Transitional Cell Carcinoma of the Bladder (STCCB) is important since conventional methods are often insufficient for prognostic purposes. We studied the proliferation activity and the DNA ploidy status of 60 pTa and pT1 Superficial Transitional Cell Carcinoma of the Bladder in relation to grade and recurrence rate. The proliferative activity was investigated by measuring the PCNA expression in paraffin embedded tissue sections. The DNA content was studied in Feulgen stained imprints by image analysis technique using a SAMBA 2005 analyser. According to our measurements a statistically significant difference was found in PCNA expression among tumors grade I, grade II, grade III (F = 5.43, p < 0.001), between tumors of the same grade with, and without recurrence (p < 0.001); and between recurrent and non-recurrent tumors (T58 = -6.03, p < 0.001). A statistically significant difference was also observed concerning the DNA-index among grade I, grade II and grade III (F = 4.81, p < 0.01), and between recurrent and non-recurrent tumors concerning the DNA DNA ploidy status (DNA-euploid vs. DNA-aneuploid tumors) (X2 = 24.96, p < 0.001). The recurrence status is also strongly influenced by the proliferation rate and the DNA ploidy status of tumors (X23 = 41.19, p < 0.001). No cases recurrence were found in the group of DNA-euploid tumors with PCNA. expression lower than 30%, in contrast a very high percentage of recurrence in patients with DNA-aneuploid tumors with PCNA expression higher than 30%. Although a small proportion of cases could not be included in me previous categories, STCCB may be classified in to main groups concerning the risk of recurrence. In keeping with this view of proliferation rate and DNA ploidy status could provide useful information, on the potential malignancy of Superficial Transitional Cell Carcinoma of the Bladder. However further studies are required to establish the clinical utility of these parameters.