CT scans of the pelvis in 132 patients with bladder tumor were reviewed. Calcifications in the bladder tumor were found in 11 men (8%) including transitional cell carcinoma (n = 6), mucinous adenocarcinoma (n = 4), and malignant mixed mesodermal tumor (n = 1). Calcifications in transitional cell carcinoma were located on the surface of the tumor in all 6 cases: they were nodular in 4 cases, nodular and arched in one, and plaque-like massive calcification in one. In mucinous adenocarcinoma multiple fine punctate calcifications were scattered within the mass in all 4 cases. The CT appearance of calcifications in bladder tumors may be helpful in predicting the histologic type of the tumor.