Introduction <p>Lactic acidosis frequently accompanies diabetic ketoacidosis. The cause of lactic acidosis, its effects on treatment success, and the related factors remain unclear. This study identified the key factors contributing to lactic acidosis in diabetic ketoacidosis and their implications for treatment success.</p> Materials and methods <p>In total, 102 patients with diabetic ketoacidosis were included in this study. The 42 patients with lactic acidosis and 60 patients with normal lactate levels were compared in terms of laboratory and clinical follow-up. Patients treated with metformin and SGLT-2 inhibitors were compared to those who did not use them in terms of ketoacidosis and lactic acidosis.</p> Conclusion <p>A relationship has been found between lactic acidosis observed in diabetic ketoacidosis and glucose, presence of infection, kidney function, potassium level, and duration of diabetes. Inflammation, renal dysfunction, and degree of acidosis affect the duration of intensive care and hospital stay. Lactic acidosis had no effect on the duration of the intensive care or hospital stay.</p>