In an attempt for utilization of Dill (Anethum graveolens) and Parsley (Petroselenium crispum) essential oils because of their flavoring and antioxidative activity. The aim of the study is to investigate the effect of essential oils as anti-diabetic or antihyperglycemic on the occurrence of oxidative stress in serum of induced diabetic rats by measuring the extent of oxidative damage as well as the status of the antioxidant defense system. Albino rats weighing (140-160gm) were injected with STZ (50 mg/kg) intraperitoneally for induction of diabetes mellitus. Rats were divided into 11 groups (each 6 rats) of non-diabetic, diabetic nontreated and diabetic treated rats with essential oils and its mixtures. After 6 weeks, the diabetic rats fed on essential oils significantly decreased levels of blood glucose and significantly increased insulin level. The treatment also resulted in a significant improvement in lipid profile. However, a significant increment in the activity of reduced glutathione was observed in blood of diabetic rats treated with all of essential oils and its mixtures. Since the study of induction of the redox enzymes is considered to be a reliable marker for evaluating the anti-peroxidative efficacy of the essential oils, these findings suggest a possible anti-peroxidative role derived from such essential oils.