Twenty-seven consecutive cases with a prospective diagnosis of cancer of the gallbladder were analyzed to clarify the computed tomographic (CT) and ultrasonographic features, behavior, and prognosis of intraluminal papillary carcinoma (n = 7) of the organ. With CT and ultrasonography, these intraluminal carcinomas were further classified into 3 subtypes: single polyp, multiple polyp, and jam-packed gallbladder. Preoperative diagnosis, evaluation of local invasiveness, and detection of metastatic lesions were reliably done. Carcinomas of this type were locally less invasive, less frequently metastasized, and resulted in a longer survival than the other massive and thickened-wall carcinomas.