The prevalence of retinal vascular abnormalities in children and adolescents with essential hypertension. We studied 97 children and adolescents with essential hypertension by evaluating photographs of the optic fundus and fluorescein angiography. Photographs were examined for the presence of arteriolar narrowing, tortuosity, and arteriovenous nicking. Intraobserver and interobserver variability in determination of abnormalities was low with agreement of 75% for narrowing, 90% for tortuosity, and 100% for arteriovenous nicking. The prevalence of abnormalities was 41% (95% confidence interval, 31% to 50%) for arteriolar narrowing, 14% (95% confidence interval, 19% to 21%) for tortuosity, and 8% (95% confidence interval, 5% to 11%) for arteriovenous nicking. Of 97 patients, 50 (51%) had one or more abnormality. Retinal abnormalities are relatively common in young patients with essential hypertension. 