Background: Diabetes mellitus is known to cause cognitive impairment that can be possibly attributed to deficient levels of leptin in diabetic animals. This study was undertaken to study the effect of administration of leptin on spatial learning, memory and blood glucose levels in diabetic rats.Methods: Rats were divided into three groups. The first group was the control group. Diabetes was induced in groups 2 and 3 by streptozotocin (STZ) injection (60 mg/kg) intraperitoneally. Group 2 received saline while group 3 received leptin (0.1 mg/kg) subcutaneously for 10 days from 4th day of STZ administration. Behavioural assessment was done in T maze after 21 days of the last injection of leptin. Blood glucose levels were also analysed.Results: The number of correct arm entries decreased while time spent being immobile and time spent to reach the correct arm increased in the diabetic group when compared to the control group and correct arm entries increased while time spent immobile and time spent to reach the correct arm decreased with leptin treatment when compared to the diabetic control rats. Blood glucose levels increased in the diabetic rats while leptin administration reduced blood glucose levels in the group 3.Conclusions: Our study suggests that leptin can improve learning and memory while also producing a slight reduction in the blood glucose levels in diabetic rats.