Blocking the formation of angiotensin II with converting enzyme inhibitors is an established intervention for kidney disease. The advent of antagonists of the angiotensin II receptor has increased the options for inhibiting the renin-angiotensin-aldosterone system. In adults, angiotensin II antagonists have antihypertensive and antiproteinuric effects similar to those of converting enzyme inhibitors and an adverse effect profile similar to that of placebo. In children, no information is available on angiotensin II antagonists. A total of 20 children (aged 4 to 17 years) with chronic kidney disease received the angiotensin II antagonist irbesartan given once daily. They had hypertension (n=11), overt proteinuria (n=3), or both (n=6). At last follow-up, 2 to 17 months after starting irbesartan (median dosage: 3.3 mg/kg body weight daily), arterial pressure was significantly reduced: the systolic value by 16 [6–22] and the diastolic value by 11 [4–22] mmHg (median and interquartile range). In nine patients with proteinuria, the urinary albumin/creatinine ratio significantly decreased by 145 [105–209] mg/mmol. The frequency of reported adverse events was similar before and with irbesartan.