Natural and synthetic meat additives approved by Food and Drug Administration "FDA" are commonly used to maintain or improve safety, nutrient value, taste and texture. Although many of the 3,000 these additives enhance meat supply, others are the subject of fierce controversy. The present study investigated the hazardous effects of sodium nitrite and monosodium glutamate "MSG" used in manufacturing of meat on some hematological, serological parameters and histopathological changes in male albino rats. Manually processed meat supplemented with doses of sodium nitrite and Monosodium glutamate "MSG", below, within and over the permissible limits, was fed to male rats for 30 days. All the used doses sodium nitrite and MSG, below, within and over the permissible limits, induced significant decrease in hemoglobin content and some hematological parameters, significant increase in serum levels of aspartate aminotransferase "AST" and alanine aminotransferase "ALT", urea and creatinine as well as various pathological changes in liver, kidney, brain and tests. The severity of these changes increased from mild to severe by increasing the concentrations of both sodium nitrite and MSG. In conclusion, the obtained data indicated that prolonged use of sodium nitrite and MSG, even within the permissible limits according to EOS (2005), was unsafe for consumer because they cause anemia, liver and kidney dysfunctions, damage to brain cells in association with deleterious effect on male fertility. Consequently, it is not recommended to use these meat additives in meat even within the permissible limits.