A 41-year-old woman, who presented with (apparent) essential hypertension, was treated with atenolol and candesartan. This treatment, however, was unsuccessful. After the addition of hydrochlorothiazide (HCT) to the combination, she developed hypokalaemia with muscle cramps and weakness. This hypokalaemia persisted for more than 4 weeks after discontinuation of HCT and starting potassium suppletion. As a result of polyuria (> 4000 ml/day) found in a 24-hour urine collection, it was discovered that the patient drank at least 3 litres of liquorice tea a day. She had denied eating liquorice sweets, a well-known cause of hypertension in the Netherlands, but no one had thought of asking her if she drank liquorice tea. Blood pressure and serum potassium normalized about 2 months after she stopped drinking liquorice tea, and medication was withdrawn. In a patient presenting with hypertension and hypokalaemia, who denies eating liquorice sweets, one should consider the consumption of other products containing liquorice such as liquorice tea. In the Netherlands liquorice tea is increasingly popular and has recently become available on a large scale. Therefore more cases such as the one described may be expected in coming years.