The prevalence of renovascular disease is estimated to be 3%-5% in pediatric patients with hypertension. The utility of non-invasive imaging tests has not been evaluated in children, and renal arteriography remains the diagnostic test of choice. However, there are no established guidelines for the application of this test and information is not available about the likelihood of detecting an abnormality if an arteriogram is performed in children with hypertension. Therefore, we reviewed the yield of renal arteriography in pediatric patients if the test was performed based on the following two criteria: (1) severe hypertension exceeding the 99th percentile for age and sex or (2) failure to control high blood pressure with one antihypertensive drug. During the period 1983-1998, 28 children (mean age 11.7 years) who satisfied one of the above criteria underwent renal arteriography to investigate hypertension. None of the patients were renal transplant recipients. The average duration of hypertension was 11 months and the peak blood pressure was 168/107 mmHg. The renal arteriogram was abnormal in 12 patients (43%). Unilateral renal artery stenosis was the most-common abnormality. When the patients were divided into two groups - those with an abnormal or normal test result - they did not differ in age, sex, or racial distribution. The peak systolic blood pressure was higher in children with an abnormal renal arteriogram (P<0.05). Among those undergoing the arteriogram on the basis of the first criterion, i.e., severe hypertension, 11 of 23 (48%) studies were abnormal. Five children had an arteriogram based on the second criterion--failure to control the blood pressure with one medication--and in 1 patient (20%) the test was abnormal. We conclude that the prevalence of renovascular disease in a population of hypertensive children subjected to renal arteriography is around 40%. Two clinical criteria--namely severe hypertension or failure to control hypertension effectively with one drug--are useful to guide the application of renal arteriography in children with hypertension.