Background Euglycemic diabetic ketoacidosis associated with SGLT2 inhibitors is a rare, relatively new and potentially fatal clinical entity, characterized by metabolic acidosis with normal or only moderately increased glycemia. Its mechanisms are not completely understood, but involve increased ketogenesis and complex renal metabolic dysfunction, resulting in both ketoacidosis and hyperchloremic acidosis. We report a rare case of fatal empagliflozin-associated acidosis with profound hyperchloremia and review its pathogenesis. Case presentation A patient with type 2 diabetes mellitus treated with empagliflozin underwent an elective hip replacement surgery. Since day 4 after surgery, he felt generally unwell, which resulted in cardiac arrest on the day 5. Empagliflozin-associated euglycemic diabetic ketoacidosis resulting in severe hyperchloremic acidosis was identified as the cause of cardiac arrest. Conclusions This case documents the possibility of severe SGLT2 inhibitors-associated mixed metabolic acidosis with prevailing hyperchloremic component. Awareness of this possibility and a high degree of suspicion is crucial for correct and early diagnosis.