A 26-year-old woman with acute myeloid leukemia underwent allogeneic peripheral blood stem cell transplantation from an HLA-identical brother. Eighteen days after transplantation, the patient developed grade II acute graft-versus-host disease (GVHD) and was treated with corticosteroids. On day 38, the patient complained of eye pain and lacrimation. A slitlamp examination revealed corneal ulcers and pseudomembranous formation in both eyes. Histologic and immunohistochemical examinations of the pseudomembrane disclosed an infiltrate dominated by T cells. A cytogenetic study of the pseudomembrane by fluorescence in situ hybridization identified a Y chromosome in the infiltrated mononuclear cells. Surveillance cultures from conjunctival swabs were negative. Thus, we diagnosed these ocular manifestations as an ocular involvement of acute GVHD.