Imidacloprid (IMI) [1-(6-chloro-3-pyridylmethyl)-Nnitroimidazolidin -2-ylideneamine] is a member of a relatively new class of insecticidal chemistry, the chloronicotinyl neonicotinoid compounds. It was introduced into commercial use only in the last decade and is increasingly used worldwide. It is the most important systemic insecticide and has a wide diversity of uses: in agriculture, on turfs, on pets and for household pests. According to the world health organization (WHO) and United States Environmental Protection Agency this compound is categorized as a “moderately toxic” Class II or III requiring a Warning or Caution labels on marketed products. IMI is rapidly and almost completely absorbed from the gastrointestinal tract, and eliminated via urine and feces. The most important metabolic steps include the degradation to 6-chloronicotinic acid (6-CINA), neurotoxic agent.There are many previous epidemiologic studies about insecticides exposures and semen quality that mainly focused on occupational exposures among pesticide sprayers.There are some reports that show IMI has an adverse effect on the reproductive system. Histopathological changes have been widely used as significant biological markers for environmental toxicity.In vivo studies demonstrated that IMI and other neonicotinoid pesticides could adversely affect mammalian reproductive organs leading to retardation of testicular development, damage to spermatogenesis, decrease in sperm quality and change of ovary morphology. Added to that the developmental retardation in mammalian fetus.