E-cadherin expression was investigated in 30 patients with urothelial cancer (bladder; 27, ureter; 2, urethra; 1) by an immunohistochemical method. Twelve out of 22 patients with strong and homogeneous expression of E-cadherin (preserved) had grade 1 tumors, while all 8 patients with heterogeneous, weak and homogeneous, or lost expression of E-cadherin (reduced) had grade 2 or grade 3 tumors. Only 2 out of 22 patients with preserved expression had invasive tumors (> or = pT2), whereas 6 out of 8 patients with reduced expression had invasive tumors (p = 0.002). Three out of 4 patients with metastasis had reduced expression and 2 of them died. These findings suggest that urothelial tumors with reduced expression of E-cadherin have high grade and high stage, and E-cadherin expression could be one of the prognostic factors.