In order to assess the incidence and the determinants of hypertensive vascular changes in the retina of patients with coarctation of the aorta, fifty (37 male and 13 female) were analyzed. The mean age of the group was 18.7 +/- 10.3 years. No one had evidence of nephropathy. Different degrees of hypertensive retinopathy (Puig-Solanes classification) were observed in 54%. Of the patients, no one had papilledema. Retinal vascular damage was not related to either age or sex. The group of patients with retinal vascular lesions had a mean level of systolic arterial pressure higher than the group with normal retinas. Multivariant statistical analysis of the results permitted the identification of systolic arterial pressure higher than 150 mm Hg, age greater than 15 years and cardiomegaly as the three variables more frequently associated with retinal vascular lesions. Surgical correction of the aortic malformation resulted in normalization of both systolic and diastolic arterial pressures in 98% of the total number of patients as determined one year postoperatively. It is concluded that, in coarctation of the aorta, vascular damage of the retina appears to have an incidence that is similar to that observed in patients with other forms of systemic arterial hypertension. The development of these retinal lesions in patients with coarctation of the aorta would seem to be determined by the severity and duration of the hypertensive process.