LD50 of some volatile oils of Anethum graveolens (common dill), Foeniculum vulgare (fennel), Artemisia herba-alba (wormseed plants) and Salvia officinalis (sage) were 1350, 1075, 937.5 and 1950 mg/kg b. wt., respectively in mice following subcutaneous injection. The volatile oil  extract of dill and fennel decreased the blood glucose level of normal rats at one hour. While, that of sage and wormseed plants produced a significant hypoglycemia in rats at one and three  hours. The high blood glucose level of alloxan diabetic rats were significantly decreased at one and three hours after injection of the oily extract of dill, fennel, wormseed plants and sage. It is concluded that the volatile oil of common dill, fennel, wormseed plants and sage have an antidiabetic effect.