The lipid changes that occur in the eyes and aortas of male Dutch belted rabbits maintained on 1% dietary cholesterol for 1 to 3 months were studied. In the cornea, iris, ciliary body, and aorta, the most noteworthy lipid change was in tissue cholesterol, which increased with increased time of feeding cholesterol. The phospholipid content of all the tissues increased to a lesser extent but followed the same pattern as cholesterol with respect to time. No changes in tissue triglyceride could be detected during the experimental period. The iris had the capacity to accumulate large amounts of cholesterol. The total iridic tissue (average wet weight, 75 mg/rabbit) accumulated an average of 10.2 mg of cholesterol after the rabbit had eaten a 1% cholesterol diet for 3 months; the average increase was 14.2 mg in aortic tissue (average wet weight = 380 mg/rabbit). The severity of disease graded visually correlated with the cholesterol concentration in the cornea and aorta. Using cholesterol concentration as the criterion, no significant correlation between aortic and corneal disease was found (P>0.10), but a good degree of correlation (P<0.01) existed between the severity of iridic and aortic involvement over the 3-month experimental period.