Semen samples were obtained from 153 patients attending the Centre de recherche en Reproduction Humaine et en Démographie (CRRHD, Bénin) and seminal neutral alpha glucosidase activity was evaluated. Semen contains testicular and accessory gland secretions. Oligozoospernia asthenozoospernia and leucospermia are involved in reducing the fertilizing ability of the spermatozoa. The present work was undertaken to evaluate the variations of seminal alpha glucosidase activity as a specific epididymal enzyme marker in these diseases. A significant positive correlation was demonstrated (P < 0.01) between alpha glucosidase activity and (1) number of spermatozoa in oligozoospermic and normozoospermic men (2) motility of spermatozoa in asthenozoospermic men. No correlation occurred between alpha glucosidase activity and leucospermia. The results of the present study suggest that alpha glucosidase specific activity of the semen was involved in the maturation and acquisition of motility by the germ cells. Otherwise, in our sample, epididymis is scarcely involved in various inflammatory diseases of the reproductive tract.