Type 2 diabetes mellitus (T2DM) is known to be associated with endothelial dysfunction (ED). Reducing ED can attenuate the occurrence of cardiovascular diseases. One of the indicators of ED is decreased coronary blood flow (CBF). Sodium-glucose co-transporter 2 inhibitors (SGLT-2is) are known to directly improve ED in both euglycemic and hyperglycemic conditions and have been shown to decrease the incidence of major cardiovascular events. We aimed to investigate whether SGLT-2is improves CBF in patients with T2DM, who have angiographically normal or nearly normal coronary arteries. In this single-center retrospective study, all patients who underwent coronary angiography between January 2017 and September 2022 were screened. We designed the study by dividing the patients into two groups - those who used conventional antidiabetic medications (CAM) together with SGLT-2is (patients using an SGLT-2 inhibitor for at least 3 months) and those who used only conventional antidiabetic medications. Of the 18,205 patients who underwent coronary angiography, 5,040 patients had T2DM. After exclusion, 288 patients were divided into two groups - those who used CAM together with SGLT-2is and those who used only CAM. CBF was assessed by thrombolysis in myocardial infarction (TIMI) frame counting. Two hundred eighty-eight patients who had T2DM and met the inclusion criteria were included in our study. The patients were divided into two groups - those who used CAM together with SGLT-2is (n = 75) and those who used only CAM (n = 213). The median age in the group that used CAM together with SGLT-2is was 55 (51-64), where 52 (69.3%) patients were female. The mean TIMI frame count (TFC) was 23.5 in the group using CAM + SGLT-2is and 27.5 in the group using only CAM. In the multivariable linear regression analysis, the mean TFC was significantly lower in the group using CAM together with SGLT-2is compared to the group using only CAM [β-coefficient = -12.766, 95% Cl: -5.304; -3.887, p < 0.001]. Moreover, there was a statistically significant correlation between an increase in BMI and hemoglobin with an increase in the mean TFC [β-coefficient = 3.018, 95% Cl 0.037-0.175, p = 0.003 and β-coefficient = 2.316, 95% Cl 0.033-0.405, p = 0.021, respectively]. We have demonstrated that the use of SGLT-2is improves coronary artery blood flow in patients with T2DM who have normal or nearly normal coronary angiography.