Fourteen patients who received allogeneic bone marrow transplantation (BMT) were examined 100 to 220 days after BMT. Ten out of 14 patients were diagnosed as having chronic graft-versus-host disease (cGVHD) in skin, liver, eyes and other organs. These cGVHD patients also had objective evidence of oral involvement. Subjective xerostomia was experienced by 7 cGVHD patients and decreased whole saliva flow was observed in 4 cGVHD patients. However, no patient had a history of parotid swelling or notable abnormality in parotid sialography. Labial salivary glands (LSG) or 9 cGVHD patients showed atrophy and/or destruction in association with diffusely infiltrating lymphocytes. The infiltrating lymphocytes were mainly CD3+ T cells with a predominance of CD8+ cells over CD4+ cells. Lichenoid lesions on the oral mucosa were also observed in 5 cGVHD patients. Thus, thus study indicated that oral examination, including LSG biopsy, is useful in the diagnosis of cGVHD.