The predictors of retinal vascular abnormalities in patients with elevated BP have not been studied extensively in children or adults. The purpose of this study was to investigate potential correlates of arteriolar narrowing, tortuosity and arteriovenous nicking in a population of children and adolescents with essential hypertension. A total of 97 subjects, aged 6-23 years, were studied. Retinal vascular abnormalities were determined by photographs of the optic fundus which were interpreted independently by two opthalmologists. In 50 subjects (51%) there were one or more abnormalities. Potential correlates of retinal abnormalities included: (1) demographic factors, (2) body size, (3) level of BP and duration of hypertension, (4) family history of cardiovascular disease, (5) treatment with antihypertensive medication, (6) dietary sodium intake, (7) laboratory analyses, (8) the reactivity of BP and heart rate to playing a video game, and (9) cardiovascular reactivity to exercise. Using stepwise multiple logistic regression, the variables that were independently associated with the presence of retinal vascular abnormalities were family income, dietary sodium intake, fasting blood glucose, pulse pressure during mental stress and the change in SBP from rest to maximum exercise. In addition, subjects with more than one retinal vascular abnormality had higher average DBP during follow-up in the Hypertension Clinic and a smaller rise in SBP from rest to maximum exercise. Identification of these independent predictors of retinal vascular abnormalities and factors associated with more than one abnormality may provide insight into the pathogenesis of hypertensive vascular disease.