Metformin increases insulin sensitivity in obese type 2 diabetic patients (T2DM) by different mechanisms. The current study was conducted to estimate and correlate the levels of miRNA-103 and 107 in obese non-diabetic subjects as well as obese T2DM patients maintained on metformin, and the development of insulin resistance. Ninety subjects were equally recruited into three groups; obese non-diabetic control (OC), obese newly diagnosed diabetic (ONDD) and obese type 2 diabetic treated with metformin (MetD). Serum levels of blood glucose, insulin, lipid profile, glycosylated hemoglobin (HbA1c), miR103&107 expression and DICER-1 were analyzed. Serum levels of HbA1c, FBG, HOMA-IR, T.ch, TG, LDL-C and VLDL-C were increased in ONDD (p˂0.0001) compared to OC and MetD. Significant increase of HDL-C (p=0.022) was observed in MetD compared to OC and ONDD. Serum insulin was increased (p=0.004) and miR 103 & 107 gene expression (p<0.0001) in ONDD and significant down-regulation in MetD compared to OC group. Dicer levels were decreased (p<0.0001) in ONDD group and increased in MetD group compared to OC group. Both miR 103 and 107 were positively correlated with insulin and HOMA-IR, but negatively correlated with Dicer. Depending on the estimated cutoff-values of area under receiver curve (AUC), miR 103 and 107 were excellent diagnostic biomarkers for insulin resistance. Our findings indicated the clinical utility of miR103 and miR 107 in diagnosis and treatment of insulin resistance. Moreover, metformin can affect miR 103 and miR 107 through modulation of DICER-1 level