Primary localized amyloidosis is a rare disease that impairs the organs and tissue function, caused by extracellular deposition of amyloid protein. Although amyloid proteins can be deposited in localized or systemic organs, the bladder is a rare site. CT showed diffuse infiltrative mass in the left urinary bladder wall, and the left ureterovesical junction with enhancement and perivesical invasion, which mimics urothelial carcinoma. However, pathological diagnosis was localized primary amyloidosis. We report here on the CT findings of a rare case of primary localized amyloidosis of the urinary bladder with brief review of the literature.