Superficial bladder carcinoma particularly grade 2 is a heterogeneous widespread group comprising both non- invasive (pTa) and invasive (pTI) tumors. Therefore, the study of its proliferative activity by immunohistochemical detection of Ki-67 antigen is necessary to highlight the biologic behavior of such lesion. This study was performed on sixty (60) retrospective cases of primary superficial bladder carcinomas (pTa and pTI) treated by transurethral resection (n=25) or by partial cystectomy (n=35) and having 60 years average age incidence. Forty eight (80%) cases were men and all were histopathologically confirmed s transitional cell carcinoma( TCC). The most frequent category was T1 G2 (31/60-51.67%). These cases were followed up by urine cytology and cystoscopy every 6 months for 3 years and during this follow up, five had progressed. In addition, ten (10) cases of normal bladder mucosa were taken as controls. The association of growth fraction defined by Ki 67(MIB-1) antibody had been studied with tumor grade, stage, multiplicity, size and the first recurrence of the superficial neoplasms as well as with the normal control cases. The mean Ki-67 indices were 0.07% in normal urothelium, 3.3% in grade 1 6.4% in grade 2 and 19.3% in grades 3 tumors, while the values were 11.1% and 13.8% in categories pTa and pTi respectively. Also they were 11.6 % recurrent compared to 2.76% in non recurrent tumor, 19.6% in multifocal compared to 5.35% in unifocal tumor and 8.9 % in lesions > 1cm compared to 3.7% in those < 1cm moreover, the index value was significantly higher in cases with progression of malignancy compared to those without (p<0.01). in addition , the multi variant analysis showed that the Ki -67 index (p <0.005), tumor size (p<0.01) and tumor number(p<0.05) were significant risk factor for superficial bladder cancer recurrence. This study concluded that Ki-67 (MIB-1) monoclonal antibody is a good tool in defining the bladder cancer behavior and its labeling index is an independent predictive factor for recurrence superficial bladder cancer and may be associated with progression as well.