We report a case of primary localized amyloidosis of the bladder with amyloid deposits which was characterized as being of immunoglobulin light chain origin (AL) including lambda type (A lambda) and P component (AP) using the KMnO4 pretreatment method and immunohistochemical procedures. The patient was treated successfully with intravesical dimethyl sulfoxide instillation and oral administration of high-dose cepharanthin after transurethral resection. Combination therapy with dimethyl sulfoxide and cepharanthin was shown to be useful for primary localized amyloidosis of the bladder.