Purpose: The Bard Bladder Tumor Antigen(BTA) test is a latex agglutination assay that qualitatively detects the presence of basement membrane degradation complexes in the urine when the bladder tumor cells invade and destruct an extracellular matrix, called basement membrane. We evaluated the clinical significance of BTA test in the diagnosis and follow-up of patients with bladder cancer by comparing it with bladder washing cytology. Materials and Methods: The Bard BTA test was compaired to bladder washing cytology in 26 patients with bladder cancer(group I), 18 undergoing surveillance cystoscopy for previous bladder cancer(group II), and 10 suffering from other urologic diseases except bladder cancer(group III). Results: Of the group I patients, 84.6% were correctly diagnosed with the Bard BTA test compared to 69.2% with bladder washing cytology, which is statistically significant(p〈0.05). There was no difference in sensitivity according to tumor grade and stage. There was a high positive rate in group II and III patients probably due to the degenration of basement membrane by other conditions such as intravesical BCG or mitomycin instillation, infection, or prostate cancer. Conclusions: The Bard BTA test is a non-invasive, simple, rapid, inexpensive adjunct to cystoscopy, and superior to bladder washing cytology in sensitivity, but many false positive results were observed. Further clinical evaluation is warranted to determine whether the false positive results are true or the result of inadequate number of patients studied.