UNASSIGNED : The present study was designed to evaluate serum lipid profile and tumor necrosis factor-alpha (TNF-ɑ) level in diabetic rats at implantation time. Type 2 diabetes mellitus (T2DM) could affect various systems, including innate immune system and it causes chronic low-grade inflammation, increasing level of TNF-ɑ. Furthermore, T2DM is often accompanied by impaired lipid profile. Metformin and pioglitazone are used as the first and second lines of treatment for T2DM. UNASSIGNED : In this experimental study, 35 adult virgin female wistar rats, weighting 175-225 g, were randomly categorized into five groups: i. Control, ii. Sham, iii. Nicotinamide (NA)+streptozotocin (STZ) induced T2DM, iv. Diabetic+pioglitazone (20 mg/kg/day for 28 days oral administration), and v. Diabetic+metformin (100 mg/kg/day for 28 days oral administration). At the time of implantation, TNF-ɑ level in serum of rats was measured by ELISA kit. Glucose was measured using photometric method and lipid profiles were calculated by enzymatic methods. UNASSIGNED : Level of TNF-ɑ in the diabetic group was significantly higher than other groups (P<0.001). In metformin treated group, TNF-ɑ serum level was also significantly higher than pioglitazone treated group (P<0.001). Fasting blood sugar (FBS) and lipid profiles were significantly higher in diabetic group. UNASSIGNED : Metformin and pioglitazone have similar effects on glucose, lipid profiles and TNF-ɑ serum levels. Among these drugs, pioglitazone has more efficient influence on TNF-α serum level, in comparison with metformin.