An exaggerated oxidative stress has been postulated as the link between diabetes mellitus (D.M) and endolhelial dysfunction. This study aimed to investigate the possible therapeutic effect of chronic zinc administration (0.5% in drinking water) on re¬nal artery vascular reactivity and oxidative stress indices viz serum oxidized to reduced glutathione ratio (GSH/GSSG), trolox equivalent antioxidant capacity (TEAC) and lipohy-droperoxides (LPO) in experimentally-induced D.M by strep-tozotocin (STZ) (60 mg/kg i.p single dose) in rats. Using Dop-pler technique in this study indicated that chronic zinc administration significantly (p