Aim To evaluate the effect of empagliflozin on glycemia and renal filtration function in patients with stable ischemic heart disease (IHD) and type 2 diabetes mellitus (DM2) who underwent a percutaneous coronary intervention (PCI).Materials and methods This study included 40 patients with stable IHD and DM2 (age, 63 (58; 65) years; DM2 duration, 7 (4; 15) years) who had indications for an elective PCI. At baseline in the total sample, the level of glycated hemoglobin was 7.2 (6.5; 8.3)%; 48.7 % failed to achieve glycemic goals. A decrease in glomerular filtration rate (GFR) to below 60 ml/min/1.73 m2 was observed in 10.3 % of patients. All patients were divided into two group by simple randomization with successively assigned numbers. The main group consisted of 20 patients who received empagliflozin 10 mg/day in addition to their previous hypoglycemic therapy irrespective of their baseline glycemic control. Patients of the comparison group (n=20) continued on their previous hypoglycemic therapy as prescribed by their endocrinologist. The follow-up duration was 6 months. Statistical analysis was performed with the Statistica 10.0 software.Results The empagliflozin treatment improved the glycemic control; in the comparison group, no significant changes in glycemic control were observed. In both groups, GFR significantly decreased during the follow-up period; median decreases in GFR were -6.0 (-16.0; 4.0) and -8.4 (-26.5; 2.5) ml/min / 1.73 m2 in the main and comparison groups, respectively (p = 0.646). No significant changes in 24-h proteinuria were observed for patients taking empagliflozin. In the control group, the 24-h urinary protein excretion significantly progressed (p=0.011) during the follow-up period.Conclusion In patients with DM2 and stable IHD who underwent a PCI, addition of empagliflozin 10 mg/day to their current hypoglycemic therapy was associated with a significant improvement of glycemic control. The decrease in GFR during the empagliflozin treatment did not significantly differ from the value for patient receiving the other hypoglycemic therapy.