Background: Diabetes mellitus (DM) is one of the most prevalent, chronic diseases affecting majority of world population. Objective: The aim of this study was to explore the correlation between TNF-α serum levels and TNF-308 gene polymorphisms in a group of diabetic Iraqi patients. Subjects and Methods: A blood sample was taken from fifty patients suffered from type2 diabetes (T2DM), and fifty healthy volunteers as a control. TNF-α serum level was detected by ELISA and TNF-308G/A (rs1800629) gene polymorphism was assessed by high resolution melting real time PCR technique. Results: The results of estimation TNF-α level showed high elevation in patients' group (52.69±4.48 pg/ml) with high significant difference (P≤0.01) as compared with control group (23.35±1.67 pg/ml). While detection of TNF-α-308 polymorphism in patients revealed that the wild genotype GG was 1 (2%),  heterogeneous genotype GA was 19 (38%), and homogeneous  genotype AA was 30 (60%) with significant difference (P≤0.001) and even as in control GG genotype was 35(70%), GA genotype was 10 (20%), AA genotype was 5 (10%) with considerable difference (P≤0.01). The findings of correlation between TNFα level and TNFα-308 genotype in T2DM patients, revealed that a substantial increase at AA genotype patients (P≤0.01) in TNFα serum level (46.17±4.64 pg/ml) followed by GA patients genotype (29.21±2.74 pg/ml) and finally GG genotype (5.11±9.15 pg/ml). Conclusion: The result revealed that patients with (A) allele had a higher risk for T2DM; also the genotype of TNFα-308 and the serum level of TNF-α in people with T2DM and healthy control were significantly different.