Hypokalaemia is a common clinical disorder, the cause of which can usually be determined by the patient's clinical history. Gitelman syndrome is an inherited tubulopathy that must be considered in some settings of hypokalaemia. We present the case of a 60-year-old male patient referred to our nephrology department for persistent hypokalaemia. Clinical history was positive for symptoms of orthostatic hypotension and polyuria. There was no history of drugs consumption other than potassium supplements. Complementary evaluation revealed hypokalaemia (2.15 mmol/l), hypomagnesaemia (0.29 mmol/l), metabolic alkalosis (pH 7.535, bicarbonate 34.1 mmol/l), hypereninaemia (281.7 U/ml), increased chloride (160 mmol/l) and sodium (126 mmol/l) urinary excretion and reduced urinary calcium excretion (0.73 mmol/l). Renal function, remainder serum and urinary ionogram, and renal ultrasound were normal. A diagnosis of Gitelman syndrome was established. We reinforced oral supplementation with potassium chloride and magnesium sulfate. Serum potassium stabilised around 3 mmol/l. The aim of our article is to remind Gitelman syndrome in the differential diagnosis of persistent hypokalaemia.