Abstract : This study designed to compare the vital role of the inflammatory immune responses and autoimmunity in development both types of diabetic mellitus by measurement of serum IL-17 , and Anti-Gad levels among patients groups and healthy by using ELISA kits . The study included sixty DM patients were divided into two groups : 30 patients with Type I DM ( 33.7% ) , and 30 patients with Type II DM (33.7%) . In addition to 29 healthy individuals were (32.6 %) . The results indicated an elevated mean serum level of IL-17 and Anti-Gad in both patients groups , as compared with the healthy control with significant difference . Also, the findings recorded a highly significant difference in IL-17 and Anti-Gad sera levels between both types of patient groups at (P< 0. 01) . According to the correlation results between IL-17 and Anti-Gad in patients groups , the data was demonstrated that the expression of IL-17 had a significant positive correlation with expression of Anti-Gad (P< 0.05) among Type I patients . Whereas an inverse very weak correlation was observed between IL-17 and Anti-Gad with no significant (P ˃ 0.05) in Type 2 patients . we concluded the an elevated levels of IL-17A in both types of DM may be as a prognostic factor for development them in Iraqi population. We also conclude that elevated Anti-Gad in Type II DM may be an indication of the rapid development of undiagnosed insulin deficiency in latent autoimmune diabetes in adult patients .