In order to test the efficacy of topically applied cyclosporin-A in preventing corneal allograft rejection, existing rabbit models were modified to produce a new model in which the allograft reaction could be consistently initiated solely as a result of corneal transfer without any additional means of sensitisation. With this model, which reflects clinical corneal grafting more closely than many previous models, cyclosporin-A 1% drops applied to the recipient eye 5 times daily for 4 weeks inhibited corneal graft rejection. When cyclosporin-A 1% drops were applied to corneal allografts for 13 weeks, 44% of grafts remained clear 180 days after transplantation. No side effects were observed that could be attributed to topically applied cyclosporin-A.