We investigated the effect of systemic indomethacin on corneal graft survival in rabbits. Two weeks following corneal transplants, skin grafts were exchanged between donor-recipient pairs. Indomethacin was started one day prior to transplant and was continued for the duration of the study. Mean graft survival was twice as long in the indomethacin-treated group (P less than 0.001) than in the untreated rabbits.