The GC-MS analyses of purslane seeds fixed oil revealed the presence of 7 components. 9,12,15-octadecatrienoic acid methyl ester was the major constituent of purslane seeds fixed oil representing (41.18%) followed by, 9, 12-octadecadienoic acid methyl ester (27.23%). The aim of the present article is to investigate the effects of purslane fixed oil (150 and 300g/kg of diet) in obese diabetic mice for 8 consecutive weeks prior. The results showed that purslane fixed oil has antidiabetic and antioxidant actions in experimental diabetic mice. Indeed, purslane fixed oil was significantly prevented the increase in the levels of body weight, blood glucose, triglycerides, total cholesterol, LDL-C, atherogenic index and thiobarbituric acid reactive substances (TBARS) in the liver tissue and improved the insulin resistance index as well as liver reduced glutathione (GSH) and superoxide dismutase (SOD) when compared to the high fat diet (HFD) control mice. The results clearly suggest that purslane fixed oil containing 9,12, 5-octadecatrienoic acid methyl ester and 9,2-octadecadienoic acid methyl ester produced a higher anti-obesity, antiatherogenic, anti-diabetic and antioxidant activities on experimental obese diabetic mice. Taken together, purslane seeds fixed oil has potential as a preventive agent for type 2 diabetes mellitus (and possibly obesity) and deserves clinical trial in the near future.