Three children with renovascular hypertension are presented in order to demonstrate the wide clinical spectrum of this disease. Two patients had relatively minor symptoms, but one with neurofibromatosis showed frank hypokalemia, polyuria, and hyponatremia. Three different anatomical lesions were found: bilateral renal artery stenosis in the patient with neurofibromatosis, fibromuscular hyperplasia in the patient with stenosis of one renal artery, and an isolated malformation of one small intrarenal artery. The last of our patients presented a complicated diagnostic problem which required repeated arteriograms and renal vein catheterizations for differential renin assay. Renovascular hypertension should be excluded in any pediatric patient with otherwise unexplained hypertension.