Foam cell lesions were found in cholesterol-fed rabbits with induced hypertension, particularly in intimal cushions at branching sites, where permeability to horseradish peroxidase was enhanced. Permeability to horseradish peroxidase was enhanced at the edge of intimal cushions without foam cell accumulation. This finding suggests that permeability is increased before foam cell infiltration. No foam cell lesions were observed in the intima of cerebral arteries distant from branching sites, but insudation of plasma constituents here caused endothelial cells to separate from the subendothelial matrices. Foam cell lesions were absent from the cerebral arteries in normotensive cholesterol-fed rabbits.