This article reviews recent knowledge about events occurring in the epididymis that are important for sperm to fertilise eggs. Well established concepts are stated without references (see Cooper, 1986 for older literature) but recent references are included where they throw light on mechanisms of epididymal function. During their sojourn in the epididymis spermatozoa acquire the capacity to move and to fertilise eggs; they are then stored in a quiescent state prior to ejaculation. The ability of sperm to undergo the events of fertilisation are developed as a result of interactions with certain epididymal secretions. Increases in our knowledge about the genes coding for epididymal secretions has not yet been matched by similar insight into the role that these secretions play in the maturation process. However, information about the changes that occur to the sperm cells during maturation permit certain scenarios to be sketched that may reflect reality. This review is one such attempt to bring the epididymal sperm-epithelial secretion into focus.