The present study aimed to investigate the possible effects of kava kava (KK) (Piper methysticum) on the hyperglycaemia induced in rats by streptozotocin (STZ; 55 mg/kg; i.p.). Blood samples, were used to determine serum levels of glucose, insulin, total cholesterol (TC) and triglycerides (TG). Some relevant markers for oxidative stress viz., serum lipid peroxides level (measured as malondialdehyde; MDA) and total antioxidant capacity as well as serum nitric oxide (NO) level measured as nitrate/nitrite were determined. Hyperglycaemic animals received orally KK (200 mg/kg) or (500 mg/kg) on daily basis for 28 consecutive days and their effects were determined 24 h after the administration of the last dose. In addition to another group received gliclazide (5 mg/kg; p.o.) as a reference drug. Results of the present study revealed that STZ-induced hyperglycaemia is associated with decreased serum insulin level with increased level of TC and TG. Hyperglycaemia was also associated increased level of plasma MDA together with decreased total antioxidant capacity and level of plasma NO. KK was able to improve the hyperglycaemia in STZ injected rats with an increase in the serum insulin level and a decrease in the level of TG. The higher dose of KK showed a restoration of the increased serum level of TC and MDA and of the suppressed insulin and total antioxidant capacity as well as the decreased plasma level of NO. From our results it can be conclude that KK has an antihyperglycaemic effect and has the ability to attenuate some of its associated abnormalities.