Introduction: Sodium-glucose co-transporter 2 (SGLT-2) inhibitors have been shown to reduce the risk of atrial fibrillation (AF) occurrence in patients with diabetes mellitus (DM). In this prospective study, we aimed to analyze the effect of SGLT-2 inhibitors as an add-on therapy to metformin on P wave indices and atrial electromechanics in patients with type 2 DM. Methods: A total of 144 patients enrolled. Electrocardiographic indices were recorded on admission and at 3rd and 6th month of the combination therapy. P wave indices and atrial electromechanical coupling intervals were measured and compared. Results: Although decrease in P wave dispersion (62.78 ± 9.59 vs. 53.62 ± 10.65; p =.002) became significant at 6th month of combination therapy, significant decreases in P wave terminal force in V1 (37.79 ± 3.45 vs. 32.01 ± 5.74; p =.035), left atrial volume index (35.87 ± 6.57 vs. 31.33 ± 7.31; p =.042), left sided intra-atrial electromechanical delay (32.09 ± 9.17 vs. 27.61 ± 8.50; p =.016), right sided intra-atrial electromechanical delay (31.82 ± 4.92 vs. 27.65 ± 8.05; p =.042), and interatrial electromechanical delay (29.65 ± 7.52 vs. 25.96 ± 4.30; p =.044) were seen as early as 3rd month of treatment. Besides, there was no statistically significant difference between Empagliflozin and Dapagliflozin subgroups in terms of mentioned parameters. Conclusion: SGLT-2 inhibitors as an add-on therapy to metformin were shown to significantly improve P wave indices and atrial electromechanics in type 2 DM patients as early as the 3rd month of treatment. It was thought that this may be one of the underlying mechanisms of the decrease in the frequency of AF with the use of SGLT2 inhibitors.