Background: Because pesticides play an important role in agriculture field, and their use has increased, the evaluation of their toxic effects is of major concern to public health. Aim: The aim of this work was to study the propensity of dimethoate (DM) to cause hepatic function disturbance in mice. Material and Methods: Dimethoate was administered orally at doses of (20mg/kg body weight) dissolved in 1 ml corn oil [1/20 of the LD50 (380mg/kg)] once daily for 14 weeks. Biochemical parameters in serum were studied: aminotransferases (ALT and AST), alkaline phosphatase (ALP), total proteins and albumin. Liver will be examined by light and electron microscope to evaluate histopathological changes. Results: Our results indicated that: the levels of the ALT and AST, ALP as well as bilirubin, in the serum of treated rabbits showed highly significant (P<0.0001) increase compared to control animals, whereas either, total protein, and albumin were highly significantly decreased (P<0.0001).Light microscopic examination of the hepatic tissue in dimethoate treated group showed congested portal vein, dilated bile duct , hepatocytes with vacuolated cytoplasm and deeply stained shrunken nuclei and hemorrhage. While electron microscope of the same group showed areas of hemorrhage, apoptotic nucleus and necrotic areas. In conclusion: Our study demonstrated that administration of DM orally at doses of (20mg/kg body weight) [1/20 of the LD50] for 14 weeks induced disturbance in the liver function .It is recommended to do Further investigations to prove the implication of oxidative stress in liver function disturbance and study the role of antioxidant in its limitation