We reported a 44-year-old Japanese woman with generalized multiple sclerotic plaques, which showed histological findings of morphea. This patient also had an erosive lesion on her mouth; its histological findings were consistent with lichen planus. A sclerotic lesion on her thigh showed the histological findings of lichen sclerosus et atrophicus (LSA). These data suggest that similar etiologic events or closely related pathologic processes are involved in morphea, lichen planus, and LSA.