The objective of the present work was to evaluate the broadest toxic effect of some synthetic additives of colorants and/or flavors on different body organs and metabolic aspects in rats. A number of chemical food color and flavor additives are routinely added during processing to improve the aesthetic appearance of the dietary items. However, many of them are toxic after prolonged use. In this experiment, a total of 100 male albino rats of Spargue Dawley strain were divided into 10 groups: G(1) was fed basal diet and served as control, G(2): basal diet + Brilliant blue (blue dye, No. 2, 124 mg/kg diet), G(3): basal diet + carmoisine (red dye, No. 3, 70 mg/kg diet), G(4): basal diet + tartrazine (yellow dye, FD & C yellow No. 5, 75 mg/kg diet), G(5): basal diet + trans-anethole (4.5 g/kg diet) G(6): basal diet + propylene glycol (0.25 g/kg diet), G(7): basal diet + vanillin(1.25 g/kg diet), G(8): basal diet + Brilliant blue + propylene glycol, G(9): basal diet + carmoisine + trans-anethole, G(10): basal diet + tartrazine + vanillin for 42 successive days. All food colorants mixed with or without flavor additives induced a significant decrease in body weight, hemoglobin concentration and red blood cell count. Also there was a significant decrease in reduced glutathione content; glutathione-S-transferase and superoxide dismutase activities in both blood and liver compared to control group. On the other hand, a significant increase in serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, bilirubin, urea, creatinine, total protein and albumin were observed in all test groups when compared to control group. Finally, it is advisable to limit the uses of these food colorants and/or food flavor additives especially those used by children.