The primary function of the epididymis is to provide a conduit for the transport of sperm and seminiferous fluid from the rete testis to the vas deferens. However, the epididymis performs much more elaborate functions including the resorption of some of the fluid by the head of the epididymis, final maturation and development of motility in the body, and storage of sperm in the tail. Performance of these functions requires the development of an elaborate rostral to caudal gradient of epithelial specialization from the efferent ductules to the beginning of the vas deferens, which is not completed until puberty. Knowledge of the changing fetal histology described in this chapter aids in the understanding of the congenital anomalies of the epididymis that are seen in association with cryptorchidism [1], renal and ureteral anomalies, cystic fibrosis, and other underlying conditions.