In the present study male albino rats weighing 200 ± 50 g were made diabetic by injection with a single ip dose of alloxan (100 mg/kg). Another group of rats was simultaneously treated with alloxan (100 mg/kg) and a single ip dose of zinc chloride (ZnCl2) (5 mg/kg). Blood and tissue samples were collected at 24, 48 and 72 hours posttreatment in both groups. Plasma insulin was significantly higher than control 24 hours after treatment in both alloxan and alloxan plus Zn treated groups, and then decreased 48 and 72 hours post treatment in both groups. The reduction was significant after 72 hours in alloxan treated group. A reduction in pancreatic glutathione (GSH) concentration was observed in alloxan-treated rats compared with control values at all sampling times of the experiment. When alloxan and ZnCl2 were administered simultaneously, alloxan-induced reduction in pancreatic GSH was diminished, and a significant high GSH values were recorded relative to those recorded after treatment with alloxan alone 24, 48 and 72 hours post treatment. Alloxan has induced a significant increase in the serum levels of creatinine, urea and blood urea nitrogen (BUN), 24 hours after treatment, which returned nearly to their normal levels 48 and 72 hours after alloxan injection except for the levels of urea and blood urea nitrogen (BUN) which were dramatically declined 48 hours after treatment before its return to the control level 72 hours following alloxan intoxication. The concentrations of serum metabolites were unchanged due to the simultaneous treatment with alloxan and ZnCl2 as compared to their concentrations in alloxan alone-treated rats except after 48 hours where alloxan plus Zn treatment has caused a significant elevation in the serum levels of urea and BUN relative to their values in alloxan alone-treated rats. A significant increase in liver glycogen level was observed 24 hours after alloxan and alloxan plus Zn treatments. Afterwards, it was markedly depleted by the two treatments 48 and 72 hours post treatment. The current results clearly indicate that the deleterious effects of alloxan were attenuated at many points by the simultaneous treatment with Zn. Of special importance was the effect of Zn in lowering the blood glucose concentration and replenishing the pancreatic GSH content.