Background:Bladder cancer is the ninth common cancer in the world, the third common cancer among men in the Arabic and Western Asian countries. In Egypt, UC has become the most frequent type with its incidence rising from 16% to 65.8%. Tumorgrade and stage have been shown to have a strong correlation with tumor recurrence and progression to invasive bladder cancer. Β-catenin functions as part of the E-cadherin/β-catenin complex and plays a role in cell-to-cell adhesion and Wnt/β-catenin pathways have been reported to regulate urothelial homeostasis and carcinogenesis. Several studies have assessed the role of β-catenin and malignant transformation, as well as tumor progression.Objectives:Evaluation of the expression of β-catenin in urothelial bladder carcinoma and its correlation with other clinicopathological parameters of prognostic importance.Patients and methods: 50 specimens; either transurethral resection (TUR) or cystectomy will be Formalin fixed and paraffin-embedded and tissue sections will be examined histopathologically by routine H&E stain. Immunohistochemical evaluation for expression of β-catenin.Results:The age range of the 50 studied patients with UC of the urinary bladder was 17-80 years, the mean age was 55.74 years, and the median age was 58 years, with male: female ratio 6:1. The cases were immunostained with β-catenin antibody and revealed that β-catenin was expressed in all cases of invasive UC with variation in its expression as it was strongly expressed in 13/28 (72.2%), moderately expressed in 9/28 (57.1%), mildly expressed in 6/28 (40%) and didn't express in 0/28 (0%) of cases. And was expressed in 19/22 cases of non-invasive UC as it was strongly expressed in 5/22 (27.8%), moderately expressed in 5/22 (35.7%), mildly expressed in 9/22 (60%) of cases and didn't express in 3/22 (100%) of cases. β-catenin showed variation in its expression in high-grade UC as it was strongly expressed in 13/27(72.2%), moderately expressed in 8/27 (57.1%), mildly expressed in 6/27 (40%) and didn't express in0/27 (0%) of cases. Expression of β-catenin in low-grade UC was; strong in 5/23 (27.8%), moderate in 6/23 (42.9%), mild in 9/23 (60%) and not expressed in 3/23 (100%) of cases.Conclusions:Expression of β-catenin increases with increasing grades of the tumor and also it showed an increase in expression by the presence of invasion.Keywords:-B-catenin, Urothelial carcinoma