The aim of this study is to evaluate antidiabetic and antioxidant effects of methanol extract of $Talinum$ $portulacifolium$ (FORSSK) leaves (Portulacaceae) (METP) in streptozotocin induced diabetic rats. The acute and sub acute antihyperglycemic effect of two different doses (200 and 400 mg/kg,) of METP were investigated. Blood glucose level, serum insulin level, lipid profiles and biomarker enzymes were evaluated in normal and diabetic rats. Liver glycogen content, kidney and liver antioxidant enzymes were evaluated. Supplementation of METP by oral gavage significantly reduces the fasting blood glucose level. This supplementation significantly increases the glycogen level in the liver ($32.33{pm}1.453$ mg/gm) as compare to diabetic control group ($5.66{pm}0.881$ mg/gm) ($p$ <0.001). Elevated serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), and alkaline phosphatase (SALP) were decreased significantly by the treatment of METP with respect to diabetic group. The antioxidant activity was studied in liver and kidney tissues by measuring malondialdehyde (MDA), reduced glutathione (GSH) and catalase levels. In the METP treated groups, the HDL/LDL ratio was improved and cholesterol and triglycerides levels also decreased significantly. Histopathological studies of the pancreas of these animals showed comparable regeneration by METP. Glibenclamide was used as a standard at a dose of 0.5 mg/kg p.o.