Autopsy specimens of the testes and epididymis of a 32-year-old male with Fabry's disease were studied by light and electron microscopy. The characteristic ceramide deposits (lamellar inclusions, myeloid-bodies, zebra-bodies) were found in the Leydig cells as well as in the epithelial lining of both the ductuli efferentes and the ductus of the epididymis. Similar myeloid-bodies were observed in the blood vessels, connective tissue cells and muscle cells of the testicular interstitium, tunica albuginea and epididymis. In contrast, myeloid-bodies were absent or scarce in both the seminiferous epithelium and the mediastinum testis. However, the seminiferous tubules were severely affected showing reduced diameter, thickening of the tunica propria, and a few degenerated spermatogonia and primary spermatocytes. The different degrees of involvement of the testicular structures might be related to their different functions, the absorptive and permeable structures being the most severely affected. The development of testicular alterations seems to have been slow, since the patient fathered three children.