Introduction: Pesticides, today of scientific concern due to their high biological activity. Exposure of Pesticides not only reduced fertility but also embryo/fetal loss, birth defects, childhood cancer, and other postnatal or functional deficits. Carbaryl is one of the most important insecticides as it is widely produced and used which has prompted us to initiate this study. Material and methodology: The present study was conducted on 40 male Wistar albino rats as experimental animals. The rats were procured from the Animals House. The rats were divided in four groups as normal control group I, group II, group III and group IV. All the rats were group housed and were fed with standard pellet diet and water for two weeks. After two weeks, the rats of group I were left as such and rats of groups II, III and IV were given 50 mg, 100 mg and 200 mg/kg body weight/day of carbaryl drug in 0.2 ml of groundnut oil orally, 6 days/week for 60 days, respectively. After 60 days, all the rats were anaesthetized by keeping them in an inverted glass jar containing large piece of cotton soaked in anaesthetic ether. The testis were dissected out from each rat and were cut into smaller pieces. These pieces were immediately fixed in 10% formalin. The blocks were prepared for section cutting with a microtome by paraffin wax embedding method. The sections of 7 μ thickness were mounted on glass slides and were stained by H&E and Masson’s trichrome stain. Observations: There were variation in the shape of seminiferous tubules, sloughing of the germinal cells from the basement membrane, depressed spermatogenesis and loss of sperms. Some tubules are showing accumulation of cellular masses in the lumen of seminiferous tubules of testis. Conclusion:These findings are highly conclusive of reproductive toxicity produced by an insecticide, Carbaryl. Moreover, intensity of toxic effects both in peripheral and central parts increases with increase in dosage of the carbaryl drug.