Ethylene glycol monomethyl ether is an industrial solvent with wide application including being employed as an antifreeze agent in jet fuel and hydraulic fluids. It has been found to have various deleterious effects including haematological, reproductive, developmental and neurological toxicities in in vivo models. Detailed report on the effect on blood cell indices and differential leukocyte is sparse. Thus the aim of this study is to investigate the effect of ethylene glycol monomethyl ether on the blood cell indices and differential leukocyte count. Fifty male Wistar rats were weight matched into five groups with ten animals each. Group I received distilled water only. Rats in groups II-V received daily, ethylene glycol monomethyl ether at 100, 200, 300 and 400 mg/kg respectively for fourteen consecutive days. All administrations were done orally. On day fifteen, blood was collected from the animals by ocular puncture, using heparinized capillary tubes, into di- potassium ethylene diamine tetra acetic acid (K2- EDTA) specimen bottles and haematological parameters were analyzed. The white blood cell count, platelets, red blood cell count, mean cell haemoglobin, haemoglobin concentration, mean cell haemoglobin concentration and neutrophils reduced significantly (p < 0.05) while lymphocytes and mean cell volume increased significantly (p < 0.05), especially at the 300 and/or 400 mg/kg body. Ethylene glycol monomethyl ether has toxic effect on the red and white blood cell indices.