In spite of the fact that inflammation has been regarded as a localized orgeneralized defensive component of the body to different types harmful stimuli, there hasbeen becoming confirmation of its strong part in initiation or progression of different ailmentsparticularly related with cancer. Objectives: Aim of this study was to recognize the pattern ofexpression and level of intensity of COX-2 in different grades of papillary urothelial carcinomaof urinary bladder along with significance of COX 2 in tumerogenesis of urothelial carcinoma ofurinary bladder. Setting: Department of Pathology, BMSI, JPMC. Period: 1.1.2009 to 31.12.2012.Methods: The marker of COX-2 was investigated by using Immuno- histochemistry. Results:COX 2 was not detected in normal urothelium, but its intensity was expressed as 68% in lowgrade, 72 % in high grade and 80 % in invasive urothelial carcinoma. Conclusion: Results ofthe present study indicate that COX-2 as a component of inflammation play an important rolein progression of urinary bladder tumor and encourage use of COX 2 inhibitors as potentialantitumor agent.