This study was conducted to examine the relationship between the concentration of zinc and neutral alpha-glucosidase (NAG) with semen quality. Semen samples from 75 male partners of couples who were attending the Obstetrics and Gynecology Department were analyzed for semen quality. Based on sperm count, the subjects were divided into three groups. Zinc and neutral alpha-glucosidase activity were estimated in seminal plasma. Results showed that mean the alpha-glucosidase activity was lowest among the azoospermic group with respect to oligozoospermic and normozoospermic groups. Mean zinc levels were also lower among azoospermics compared to oligozoospermic and normospermic groups. The difference was statistically significant (p < 0.05). A significant positive correlation was observed between zinc levels and sperm count (r = 0.29, p < 0.05) and zinc and alpha-glucosidase activity (r = 0.31, p < 0.05) in seminal plasma. These results suggest that zinc and neutral alpha-glucosidase seem to play an important role in human reproduction.