Purpose: This study aimed to evaluate the efficacy and tolerability of dapagliflozin as an add-on or a switch therapy to lobegli-tazone plus metformin (MFM) in Korean patients with inadequately controlled type 2 diabetes mellitus (T2DM) in real-worldclinical practice. Materials and Methods: The study included 109 patients who started dapagliflozin as add-on or switch therapy to lobeglitazoneplus MFM. The primary outcome was a change in glycated hemoglobin (HbA1c) level from baseline after 12 months of treatment. Secondary outcomes included changes in fasting plasma glucose (FPG), lipid profiles, body weight, visceral fat area (VFA), andblood pressure after 12 months of treatment. Results: The baseline HbA1c was 8.3±1.3% (8.7±1.5% in the add-on group and 8.1±1.0% in the switch group). After 12 months,mean HbA1c decreased (-0.91%) in all patients (p<0.05) (-1.39% in the add-on group and -0.63% in the switch group). Significantreductions in FPG were also observed in both the add-on and switch groups (-54.37 mg/dL and -24.68 mg/dL, respectively). Over-all, there was a significant improvement in serum triglyceride (-24.74 mg/dL), low density lipoprotein cholesterol (-7.92 mg/dL),body weight (-2.98 kg), VFA (-9.00 cm2), and systolic blood pressure (-8.67 mm Hg). Approximately 35.8% of patients achievedHbA1c <7.0% after 12 months. Conclusion: Dapagliflozin, as an add-on or a switch therapy to lobeglitazone plus MFM, can be a suitable alternative for Korean pa-tients with inadequately controlled T2DM. The combination therapy resulted in significant reductions in HbA1c levels, body weight,and blood pressure.