Clinically bladder tumors can be easily diagnosed on cystoscopic examination and biopsy in the patients with silent hematuria, terminal dribbling and dysuria. But for the evaluation of the extent of tumor invasion. the author performed both barium-air double contrast and triple-fractionated cystography on 16 patients suspected to be bladder tumor on cystoscopic examination in the radiologic department of B.N.U.H. from September 1982 to August 1983. The obtained results were summarized as follows. 1. On barium-air double contrast cystography and triple-fractionated cystography, 13 cases were concluded as bladder tumor, and 3 cases were consistent with findings of chronic inflammation out of the total 16 cases. 2. After operation of 15 cases, 12 cases were confirmed pathologically as transitional cell carcinoma, 1 case as prostatic hypertrophy, and 2 cases as chronic inflammation. 3. Among 9 cases of transitional cell carcinoma having the evidence of muscle invasion on triple-fractionated cystography, 8 cases were confirmed as more than stage B1 on pathologic study, and the other as chronic inflammation. 4, In detecting multiplicity, presence of ulceration, and evaluation of nature of tumor surface, barium-air double contrast cystography was more excellent than cystoscopic results. 5. Cases presenting both ulceration and cauliflower appearance on barium-air double contrast cystography was more than grade 111 on microscopic evaluation. 6. In conclusion, the author considers the barium-air double contrast and triple- fractionated cystography are easy to perform, resonable in price and have relatively high accuracy in tumor detection, staging and grading.