Hyperkalaemia is a condition of excess potassium level that occurs as a result of increased intake, or reduced renal clearance, or both. In a severe condition, hyperkalaemia is a medical emergency that can be life-threatening especially if recognised late and left untreated. There are many causes of hyperkalaemia. However, eating durian fruit in the background of impaired kidney function is a very rare occurrence. In this article, we report a case of an elderly lady who presented with a life-threatening hyperkalaemia as a result of eating large amount of durian fruit while having multiple diarrhoeal episodes due to acute gastroenteritis that led to acute kidney injury. She was successfully treated and was discharged well. The objective of this case report is to share the rare cause of a life-threatening hyperkalaemia where prompt diagnosis and treatment initiation are crucial to prevent mortality.