The application of x-rays in the diagnosis of gall-bladder diseases is an old, well-known method, but since this is used mainly in taking a simple photograph, it is difficult to obtain a good roentgenological picture. Recently with the successive advent of excellent opaque substances such as Biligrafin, Telepaque and Priodax the diagnosis of gall bladder diseases has become quite easy, but two cases on which we report here are, on the contrary, the cases whose diagnosis has been made more difficult on account of the appearance of these excellent contrast media. This "Porzellangallenblase" is an extremely rare disease and it was first reported by H. D. Flörchen (1929) in the "Zentralblatt d. Chirurgie". It presents a piture identical with the one taken at the time when opaque substance is administered. As for the symptoms, the patient mainly complains of something similar to gall-stone; and in our cases, one was suspected of kidney stone and the other was of gall-bladder disease. Both of these were discovered at the x-ray examinations of the stomach, and each in their roentgenograph presented the stone in their bile duct. In addition their roentgenograph of the gall-bladder gave the picture identical with the one taken when opaque substance had been given. We present this case report as these are very rare cases among Japanese people in the light of available literatures.