Although bilateral megaureters are not an infrequent occurrence in the urinary tract, bilateral megaureters associated with bilateral renal pelvis dilatation and a giant urinary bladder appear to be rare. In this paper, a cadaver case of an adult Japanese male with bilateral megaureters is described. In addition to describing and illustrating this case, the anatomy and etiology of these anomalous structures is discussed with a brief review of the literature.