There is considerable evidence, suggest that, consumption of food additives monosodium glutamate (MSG), places humans at risk and  the greatest risk is faced by children. The present work aimed for explaining the risks of excessive use of recent food additives MSGasa flavor enhancer and to study the role of black seeds extract Nigellia sativaas a natural and safe product in modulating effect of renal structural changes in female mice. Eighty female Swiss albino mice Musmusculus (2 months old, 20-25 g) divided into 4 groups (20 females each). The first group was used as control one (given distilled water only without MSG and/ or NS). The second group, (given orally a dose of 8 mg MSG/kg of body weight in distilled water). The third group, (given orally a dose of 180 mg powder NS/kg of body weight suspended in distilled water )and the fourth group, (given orally a dose of 8 mg MSG and 180 mg powder NS/kg of body weight in distilled water). Mice were sacrificed at the end of 10 weeks to remove kidneys for histological and histochemical studies. Histological and histochemical investigations of kidney of MSG group showed several changes include dilation and congestion of some blood vessels, certain cells of convoluted tubules affected comprising cellular swelling, hydropic changes, necrosis, enlarged dilation of several convoluted tubules. Investigation also showed infiltration of large number of inflammatory lymphocytes and abnormality in the pattern of kidney tissues and distortion of some glomeruluithat appeared enlarged or lobulated and sometimes congested with red blood cells.  Also increased intensity of collagen fibers, proteins and lipids with the general lack of glycogen granules was observed as compared with controls one. The result of this work showed the role of Nigellia sativa extract as a natural and safe product in modulating renal structural changes in female Swiss albino mice treated with MSG and explained the risks of excessive use of MSGas a flavor enhancer.