The dimethoate is considered as one of most important organophosphorus pesticides that vastly used in agriculture in many countries especially in Iraq which caused different diseases in plants, animals and man. In present study we investigated the histopathological and hematological changes in rabbits resulting from chronic dimethoate intoxication. The treated groups (G2, G3 and G4) received dimethoate orally (10, 25 and 50 mg/kg of B.W.) respectively for two months while the control group (G1) was given water for the same period. The hematological results showed significant decrease in red blood cells counts and hemoglobin values (P< 0.05) in treated groups especially G3 and G4 compared to G1 control group. While the total W.B.Cs counts showed variables values without significant differences between treated groups and control group. The histopathological lesions in organs are dose concerning and include mild hepatocellular degeneration and hepatic necrosis ,hemorrhage with extensive periportal fibrosis, chronic inflammatory cells infiltrations mainly lymphocytes and macrophages in addition to liver fibrosis and cirrhosis and biliary hyperplasia with cholangitis occurred only with toxic doses of dimethoate especially G4, also there degenerative changes and necrosis in kidney and heart, hemosiderosis and hemorrhage with lymphoid depletion in spleen , In brain, there is extensive demyelination and perineruonal edema and perivascular leukocytes cuffing and extensive focal gliosis and the lungs showed congestion with thickened alveolar walls because of slight infiltrations of inflammatory cells mainly lymphocytes and macrophages also there is severe pulmonary hemorrhage and edema with severe emphysematous area and atelectasis in pulmonary tissue. It was concluded that dimethoate induces different histopathological lesions in different organs in rabbits especially in liver which causes hepatocellular degeneration, biliary hyperplasia and cholangitis with hepatic fibrosis and cirrhosis and causes significant decrease in red blood cells counts and hemoglobin values in treated groups compared to the control.