10.22376/ijpbs.2019.10.1.p1-12 Volume 2 Issue 4 2011 (October - December) Effect of a combination of pesticides, viz. Delatmethrin 1% + Chlorpyriphos 35% EC, has been studied on the reproductive toxicology of wistar rats. Male rats were exposed to test substance at the dose level of 15, 25, and 35-mg/kg body weight for a consecutive period of 20 weeks. At the end of the experimental period, all the animals were subjected for necropsy, sperm parameters such as motility, testicular sperm-head count, epididymal count and morphological evaluations were carried out. The treatment is reported to induce significant alteration in sperm motility, testicular sperm-head count and epididymal count at 35 mg/kg body weight dose group. Results suggested that the pesticide combination, viz (Delatmethrin 1% + Chlorpyriphos 35% EC) used in the present investigation inhibit the sperm production and motility either directly or indirectly. Shivaraj, Dr. M. David And Dr. Ravi. K. B Deltamethrin, Chlorpyriphos, Sperm motility, Testicular Sperm-head count, Epididymal count, Wistar rats, Spermatotoxicity 261-268