• Rabbits immunized with a preparation of Staphylococcus aureus cell walls (CWs) mixed with complete Freund's adjuvant (CFA) showed vascularized, elevated nodular infiltrates of the cornea or peripheral corneal infiltrates separated from the limbus by a lucid interval in 14 of 20 eyes (70%) after topical challenge with viable S aureus. The number of corneal lesions after topical challenge in this group differed statistically from that in normal rabbits or in rabbits immunized with S aureus peptidoglycan (PG) mixed with CFA, protein A (PA) mixed with CFA, or normal saline mixed with CFA. Skin tests in rabbits immunized with CWs mixed with CFA showed Arthus reactions to CWs, PG, and ribitol teichoic acid and delayed hypersensitivity reactions to CWs and PG. The results of the present study indicate that immunization with CW antigens of S aureus is associated with the development of phlyctenulae and catarrhal infiltrates of the rabbit cornea.