Forty adult Swiss albino mice of either sex divided into 4 groups of 10 mice in each group were used to evaluate the ameliorating effect vitamin E on hematological and serum biochemical changes induced by subchronic chlorpyrifos (CPF) exposure. Group I (control~C/oil) and group II (VE) were administered corn oil (2 ml/kg) and vitamin E (75 mg/kg), respectively. Group III was administered CPF (21.3 mg/kg~ 1/5th LD50) only while group IV (VE + CPF) was pretreated with vitamin E (100 mg/kg) followed by CPF administration, 30 min later. The regimens were administered orally by gavage, every other week days for a period of ten weeks. The mice were evaluated for signs of toxicity and weekly body weight changes. At the end of the dosing period, blood samples collected were analyzed for packed cell volume, total red blood cell, white blood cell and total protein. The sera obtained from the blood samples were analyzed for the levels of Na+, K+, Cl-, total protein, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and malonaldehyde. The results showed that pretreatment with vitamin E ameliorated deficits in clinical, body weight, hematological and biochemical changes induced by repeated CPF administration in mice, partly due to its antioxidant properties.