The relationship between angiotensin converting enzyme inhibition and hypoglycemia remains controversial. An 82-year-old, nondiabetic woman who had taken ramipril 5 mg with amiloride 5 mg for two months was admitted to the hospital because of her altered mentality. Her plasma glucose was 1.5 mmol/L and she regained her consciousness after normalization of the plasma glucose. The recurrent attacks of hypoglycemia ended when she stopped taking ramipril. Her hypoglycemia was thought to result from the combined deficiency of catecholamines and cortisol that was induced by a deficiency of angiotensin II. The glucagoninsensitivity was thought to result from a chronic elevation of bradykinin due to the ACE inhibitor, and the relative hyperinsulinemia was though to be cased by the amiloride.