Pyrethroid pesticides are used preferably over organochlorines and organophosphates due to their high effectiveness, low toxicity to non-target organisms and easy biodegradability. Cypermethrin, a type II synthetic pyrethroid pesticide, is widely used in Egypt in pest control programs in agriculture and in public health as well. The objective of the present study was to evaluate the potential of cypermethrin genotoxicity in sperm and to investigate the possible ameliorative effects of vitamins C and E on cypermethrin toxicity. This study was done on semen samples collected from 10 healthy normozoospermic volunteers. Each semen sample was divided into six aliquots. One served as control negative aliquot (group I) that was not exposed to any treatments. The second aliquot (group II) was incubated with 20 mM vitamin C (ascorbic acid) and 2 mM vitamin E (?-tocopherol). The third aliquot was exposed to cypermethrin with a dose of 10 ∝ M (group III). While the other three aliquots (IV, V, VI) were incubated with 20 mM vitamin C, 2 mM vitamin E and vitamin C & E (20 mM, 2 mM respectively) for 30 min before cypermethrin exposure. All aliquots were kept for  6 h at 37 ° C. Unexposed and exposed aliquots were analyzed for sperm concentration, motility, and viability according to WHO guidelines. Hypo- Osmotic Swelling (HOS) test and the modified alkaline comet assay were carried out on the prepared samples. There was statistically significant decrease in parameters of sperm motility and seminal function and increase in sperm DNA damage parametrers in cypermethrin group. With addition of antioxidant vitamins C and E either alone or with each other; there was statistically significant improvement in all of the parameters of sperm motion, seminal function and DNA damage parametrers and the maximal improvement was with both vitamins C & E. It can be concluded that cypermethrin can alter sperm function and induce genotoxic effect on sperms in vitro and that the antioxidant vitamins (C and E) can be useful in improving the toxic effects of cypermethrin on sperm.