Background: Chlorpyrifos CPF is one of the organophosphate insecticides that were interfered with the body’s hormones. Thyroid hormones are necessary to maintained normal metabolism, growth and development and the disturbance of their levels leads to adverse medical conditions. Ginger extract and selenium are effective anti- oxidants. Aim of the work: This study examined effect of CPF on the thyroid gland structure and function and the ameliorative effect of ginger extract and selenium. Material and Methods: forty rats were categorized into four groups. Control group I, group II: rats were given CPF at a dose of 6.7 mg/kg orally five days / week for six weeks, group III: rats were given CPF and ginger extract at a dose of 750 mg/kg orally, five days / week for six weeks. Group IV: rats were given CPF and sodium selenite 10 μg/Kg orally five days / week for six weeks, blood samples were taken for hormonal essay. Thyroid gland specimens were prepared for the histological and immunohistochemical studies. Results: chlorpyrifos induced functional toxic effect and destruction of the thyroid gland histological structures. There was a significant decrease in area % of the colloid and a significant increase in mean number of PCNA positive nuclei in comparison with the control group. Ginger extract and selenium eliminated the damage effect of CPF on the thyroid gland function and histological structure. Conclusion: CPF had adverse effects on the thyroid structure and function that could be eliminated by administration of ginger and selenium.