Retinal cotton-wool patches, not previously observed in bone marrow recipients, have been reported in three patients who received Sandimmun (cyclosporine) as prophylaxis for graft-versus-host-disease after bone marrow transplantation. These patients all had acute lymphoblastic leukemia and had received, in addition to the standard conditioning regimen, central nervous system irradiation before transplantation. We were thus prompted to examine 55 renal transplant recipients (15 of them prospectively) who were receiving cyclosporine for evidence of similar fundal changes. No cotton-wool patches were found in any of the renal transplant recipients.