Diabetes mellitus (DM) is commonly referred to as a “sugar” and it is the most common endocrine disorder and usually occurs when there is deficiency or absence of insulin or rarely, impairment of insulin activity (insulin resistance). The powdered leaves phoenix dactylifera was extracted with 400ml of 70 % v/v of ethanol and water for 5 hour in soxhelet. Alloxan monohydrate at a dose of 150 mg/kg injected intraperitonally for induction of diabetes mellitus. The extract of Phoenix dactylifera leaves was subjected to anti-diabetic activity in rats. Group-IV & Group-V received the ethanolic & aqueous extract of phoenix dactylifera leaves(500mg/kg) shown a marked reduction in blood glucose level on day 4th i.e. in ethanolic extract it was 284.76±mg/dl while in aqueous extract it was 264.76±6.65. On 10th day of study the glucose level falls up to 264.40±7.72 in ethanolic extract rat & 254.05±9.18 in aqueous extract. The results of the present study indicate that Phoenix dactylifera leaf extract was found to reduce the glucose level in animals made diabetic with alloxan. In the present investigation ethanolic extract of Phoenix dactylifera leaf showed significant anti-diabetic activity