Background: Diabetic complications are related to impaired glycemic control. The UK Prospective Diabetes Study (UKPDS) showed that metformin therapy in overweight and obese patients with type 2 diabetes mellitus (T2DM) could reduce HbA1c and complications. So, metformin has been suggested to be the drug of choice after life style modifications in patients with T2DM. Repaglinide, short-acting insulin secretagogues, has excellent anti-hyperglycemic effect and a lower risk of hypoglycemia. However, whether repaglinide can be used as an initial therapy in patients with newly diagnosed T2DM is still unconfirmed. Objectives: The objective of this study was: To compare efficacy of Repaglinide and Metformin in the Treatment of New Onset Type 2 Diabetes Mellitus. Study Design: Randomized Controlled Trial. Setting: District headquarter Hospital, Faisalabad. Period: 6 Months (Jan 2018 to June 2018). Methodology: Patients were randomly divided into two groups (A & B) by using computer generated random number table. Group A was given repaglinide 0.75-1.5 mg/day while group B received metformin 750-1500mg/day. The doses of metformin and repaglinide were adjusted according to blood glucose level. For HbA1C and FBS, blood samples were sent to pathology laboratory at the start of study and after 3 months. Follow up was ensured by reaching the patients through telephonic contact. Data was collected through self-conducted interviews using a standardized Performa. Results: In our study, mean+sd was calculated as 44.54+5.92 years in Group-A and 45.31+6.13 years in Group-B, 42.86%(n=15) in Group-A and 40%(n=14) in Group-B were male whereas 57.14%(n=20) in Group-A and 60%(n=21) in Group-B were females. Baseline mean HbA1c levels of the patients were calculated as 7.51+0.50 mmol/L in Group-A and 7.54+0.52 mmol/L in Group B, p value was 0.81. After treatment, these findings were reduced to 5.57+0.65 in Group-A and 6.4+0.49 in Group-B, p value was 0.0001, At baseline mean fasting blood glucose levels of the patients were calculated as 7.43+0.56 mmol/L in Group-A and 7.46+0.50 mmol/L in Group B, p value was 0.82. After treatment, these findings were reduced to 5.83+0.71 in Group-A and 6.29+0.67 in Group-B, p value was 0.007. Conclusion: We concluded that on comparison of Metformin and Repaglinide monotherapy in the Treatment of New Onset Type 2 Diabetes Mellitus in terms of mean fasting blood glucose and mean HbA1c, both drugs reduced HbA1c and fasting blood sugar but Repaglinide was found significantly better for reduction of HbA1c and fasting blood sugar when compared to Metformin.