Objective: This study was conducted to determine expression ofTLR2 in peripheral blood monocytes and the proinflammatory cytokine IL18 in type 2 diabetic obese patients to explain a possible pathophysiological link between obesity and inflammation leading to insulin resistance. Methodology:This study was conducted in Al-Zahra University Hospital .The study population consisted of 40 patients divided into 3 groups : 15 obese non diabetic patients, 15 diabetic obese patients and 10 normal body weight clinically and laboratory free served as a control group . All studied groups were subjected to clinical examination and laboratory investigations which include lipid profile, fasting blood glucose, Hb A1C, serum insulin, HOMA IR, Serum IL 18 and flow cytometric analysis expression of TLR-2 on CD14+ monocytes.Results: IL-18 levels were significantly higher in obese non diabetic group(61.5 ± 8.2 ng/l) and diabetic obese group (62.8 ± 10.9 ng/l) when compare to normal control group (26.5 ± 6.5 ng/l) (p<0.000) , while there were no significant change between obese non diabetic group and diabetic obese group regarding IL-18 levels (p 0. 713) and there was a highly significant increase in TLR-2 MFI in obese non diabetic group (9.3 + 3.2 ), diabetic obese group (16.7 + 3.4)when compared to controls group (4.5 + 1.2), also levels of TLR-2MFI were significantly higher in obese diabetic group compared to obese non diabetic group (p< 0.001) . There was a significant increase in HOMA-IR in obese non diabetic group (3.81 + 0.97), diabetic obese group (11.55+3.89) when compared to controls group (2.46 + 0.95)(p<0.0025) (P<0.001). Also levels of HOMA IR were significantly higher in obese diabetic group compared to obese non diabetic group (p< 0.00). There was a significant increase in insulin levels in obese non diabetic group (16.4 + 3.72uU/L), diabetic obese group (21.40 + 3.98uU/l) when compared to controls group (11.2 + 2.94 uU/L) (p< 0.008), also levels of insulin were significantly higher in obese non diabetic group compared to obese diabetic group (p< 0.0014). There was a significant positive correlation between TLR2 MFI and each of insulin, IL18 and BMI in obese non diabetic as well as diabetic obese patients. Conclusions:This study demonstrated that the expression of TLR-2 on CD14+ monocytes was up regulated in obese non diabetic and obese diabetic patients and was associated with inflammatory response as assessed by increased serum levels of IL-18.