This study evaluated the effects of a polyherbal formula on the plasma lipid profile and blood glucose in Streptozotocin-induced diabetic rats. A single dose of Streptozotocin (STZ), (60 mg/kg body weight) in sodium citrate buffer at pH 4.5 was used to induce diabetes intraperitoneally in 20 adult Albino Wistar Strain Rats. 25 rats were put into 5 groups: Normal, Standard, Control, Test I and Test II respectively and were sacrificed after 7days of treatment. The weight and glucose baseline were taken prior to: (1) STZ administration (2) after a week of inducing diabetes (3) after the first, third and fifth day of treatment and (4) at sacrificial time. The body weight and blood glucose level of all animals in different groups varied depending on treatment. Blood glucose test showed that there was a significant increase in blood glucose level after induction. After treatment, the normal group blood glucose level increased by 19.12 % but not diabetic, and a decrease of 10.61 %, 61.64 %, 48.19 % and 77.16 % for the Control, Standard, Test I and Test II respectively. The body weight for normal group increased by 6.29 % while the Control group, Standard group, Test I and Test II emaciated by 7.91 %, 3.35 %, 6.9 % and 5.1 % respectively. The lipid profile test showed that Test I and Test II groups have lower lipid values compare with other study groups. Results from this study clearly indicated that the polyherbal formula had hypoglycaemic and hypolipidemic effects on Streptozotocin-induced diabetic rats.