In a long-term follow-up of 52 patients with oral lesions of discoid lupus erythematosus (DLE) 8 patients showed a gradual transition of the typical DLE lesions to lesions which closely resemble leukoplakia. Histopathologically and immunopathologically the leukoplakia-like lesions generally snowed features similar to those in leukoplakias not preceded by DLE. Ultrastructurally, the leukoplakia-like lesions showed the presence of cytoplasmic tubular structures in vascular endothelium rn two out of three patients examined. The leukoplakia-like stage is considered to be an inactive or scar-like stage, which may be the mucous membrane counterpart of the atrophic scars following DLE lesions of the skin.A primary examination of a DLE patient presenting oral lesions at the leukoplakia-like stage may result in an incorrect diagnosis. Therefore, when investigating patients with leukoplakias, they should be questioned on previous or present skin lesions as well as symptoms of systemic lupus erythematosus.