A 21-year-old man with refractory acute myeloid leukemia presented with itching and tearing in both eyes 1 month after receiving a hematopoietic stem-cell transplant from an HLA-mismatched, unrelated donor. Three weeks after transplantation, he received a diagnosis of grade 4 acute graft-versus-host disease (GVHD) involving the skin, gut, and liver. An examination revealed that his visual acuity was not affected. The corneas in both eyes appeared normal, but pseudomembranes of the upper and lower tarsal conjunctivae could be seen (Panel A). The pseudomembrane of one eye was removed (Panel B), and histopathological analysis revealed fibrinous exudates, macrophages, and solitary granulocytes; no microorganisms were detected. A diagnosis of grade 3 acute ocular GVHD was made, and treatment with topical prednisolone was initiated. Acute ocular GVHD with pseudomembranes is a possible complication of hematopoietic stem-cell transplantation and is associated with a poor prognosis. In this patient, to prevent conjunctival scarring, the pseudomembranes were removed regularly until they no longer appeared, after 3 weeks of treatment. Remission of acute GVHD was achieved after treatment with glucocorticoids and with additional immunosuppression. Moderate chronic GVHD involving the skin, mouth, eyes, and fascia developed 1 year later.