Monosodium Glutamate (MSG), locally known as ''Maggi'' is one of the worlds’ most widely used food additives. It is used in modern nutrition worldwide as a flavor enhancer. MSG is widely used by Sudanese families and recently it becomes very popular in rural areas due to its availability and low price especially under the harsh economic situation of the country. Fifteen, 3-month old, both sexes Wister rats were randomly assigned into three groups. Control, low dose (5mg/kg/day) and high dose (15mg/kg/day) of monosodium glutamate, were administered orally to Wister rats weighing between (85-100 g) for 4 weeks. Liver and Kidney function tests were carried out on the blood serum. Hematological parameters where also tested and Necropsy was conducted to identify gross lesions in liver, kidney and intestine. The results show that monosodium glutamate induced an increase in body weight and significant change in the activity of liver enzymes (ALT, AST and ALP). Also, there was a significant increase in WBCs, the level of total protein and globulin, as well as increase in creatinine and Urea. Histopathological examination showed clear changes in liver, kidney and intestine tissues. These findings revealed that Monosodium glutamate consumption may have toxic effects in liver and kidney tissues especially when consumed at higher concentrations and continuous consumption may affect the function of liver and kidney.