Abstract: Objective:To investigate microsatellite instability (MSI) and it's potential clinical implications in urinary exfoliative cell of the patients with bladder carcinoma. Methods: After treated with proper method, urine spacimens from 69 individuals were analyzed by PCR for microsatellite instability and it's relation to the clinico-pathologic parameters. Results: The overall sensitivity of microsatellite instability in voided urine samples for the detection of bladder neoplasms was 59.52% (25/42). It was relatively higher in the tumor of advanced stage and grade, but there was no significance (P>0.05). It was significantly higher in recurrent cases (60.00%, 12/20) than in primary cases (80.00%, 16/20)(P<0.05). Conclusion: MSI is a potential biomarker for noninvasive detection of bladder carcinoma by assaying exfoliated cells from the voided urine specimen with PCR.