The objective of this study was to examine the hypothesis that intake of p-hydroxycinnamic acid (p-HCA) regulates blood glucose levels and hypolipidemic responses in rats with diabetes mellitus induced by injection of streptozotocin (STZ). The diabetic rats exhibited lower levels of body weight, insulin, hemoglobin (Hb), high-density lipoprotein (HDL) and higher levels of glucose, lipid profiles, lipid peroxidation markers in blood hepatic and renal tissues as compared with normal rats. In addition, diabetic rats showed decreased levels of superoxide dismutase (SOD) and catalase (CAT). Oral administration of p-HCA at the doses of 10, 20 and 40mg/kg BW. was given once daily started after the rise of blood glucose for 45days. Our result demonstrated that p-HCA administration could be lowered blood glucose, glycosylated hemoglobin, lipid profiles and significant increase in plasma insulin, hemogloblin, and HDL. In addition exert protective action against oxidative markers, TBARS and lipid hydroperoxides and improves antioxidant. The overall results suggest that p-HCA possesses potential hyperglycemic, hyperlipidemic and antioxidant activity in STZ-induced diabetic rats.