HighlightsAcute intermittent porphyria is rare.High index of suspicion is needed to diagnose acute intermittent porphyria in a patient with abdominal pain, neuro-psychiatric manifestations and hyponatremia after surgery.Once suspected, prompt intensive care management should include high calorie intake, symptomatic treatment of hyponatremia, use of safe medications and careful fluid-electrolyte monitoring in order to avoid serious complications and mortality.