Background: Mono sodium glutamate (MSG) is commonly used as a flavor enhancer. Many studies showed toxic effects of MSG on different organs. Selenium (Se) is reported to possess a strong antioxidant property. The aim of this work was to evaluate the role of selenium on hepatotoxicity, testicular toxicity induced by MSG in adult albino rats. Material and Methods: study included 55 male albino rats for 8 weeks. Rats were divided into four groups, group I(control group) consisted of 22 rats equally and randomly subdivided into 2 subgroups: Ia (-ve control group), Ib (+ve control group) received distilled water. Group II (Se group) consisted of 11 rats received sodium biselenite at a dose of (0.5ml/kg/day/orally) dissolved in distilled water. Group III (MSG treated group) consisted of 11rats received MSG at a dose of (830mg/kg/day/ orally) dissolved in distilled water. Group IV (MSG and Se treated group) consisted of 11 rats treated in the previous doses. After 8 weeks, the rats were submitted to estimate the serum levels of alanine transaminase (ALT) & gamma glutamyle transferase (GGT) levels and testosterone hormone level. Then the anesthetized rats were sacrificed & specimens from the liver and testes were taken for determination of histopathological study, immunohistochemical staining for caspase 3, oxidative stress markers [malondialdehyde (MDA) & glutathione peroxidase (GPx)] and sperm count. Results showed in MSG group significantly increased serum ALT, GGT & significantly decreased in serum testosterone, sperm count with marked histopathological changes in the liver and testis and caspase 3 activities was significantly increased in testicular and liver tissue. Also, it significantly increased MDA level and decreased GPx activity in (liver and testicular tissues). Administration of Se along with MSG produced partial improvement of hepatic and testicular morphological changes, reduction in caspase 3 expression with beneficial effect on liver and testicular parameters, In addition, it decreased MDA level and increased GPx activity in (liver and testicular tissues). In conclusion, the results confirmed the hepatic and testicular toxicity of MSG through oxidative stress. Selenium has partial protective effects against MSG induced hepatic, testicular toxicity through its anti oxidant and its anti apoptotic effects.