Metallo-elements including Vanadium (V) have strong affinity for sulfhydryl (-SH) groups in biological molecules including Glutathione (GSH) in tissues. Because of this fact it was of interest to further investigate the interaction of Ammonium Vanadate [NH(4)VO(3)] with Glutathione as a biomarker of toxicity and the role of Glutathione in the detoxification and conjugation pr(o)Cesses in whole blood components including plasma and cytosolic fraction. Effects of different concentrations of Ammonium Vanadate [NH(4)VO(3)] on the level of reduced Glutathione in whole blood components (Plasma and Cytosolic fraction) were examined. GSH depletion in plasma and cytosolic fraction was Ammonium Vanadate's concentration-dependent. Depleted GSH level was more pronounced with more incubation time period. These findings show that changes in the GSH status produced by Ammonium Vanadate could be due to either by adduct formation of Vanadium and glutathione i.e. (V-SG) or by increased production of oxidized Glutathione (2GSH +V(+5) → GSSG). This change in GSH metabolic status provides some information regarding the mechanism of toxicity by Ammonium Vanadate and the protective role of glutathione.