Introduction: Various diseases cause pigmentation of the oral mucosa. Among them, however, Laugier-Hunziker syndrome is not well known to dentists. Laugier-Hunziker syndrome is a benign pigmentary disorder characterized by the unique expression of pigmentation of the mucosa, nails and skin. In this report, we present a rare case of Laugier-Hunziker syndrome that occurred in an elderly person. Case Presentation: The patient was an 84-year-old female resident of an elderly care facility. The institutional dental hygienist reported that she was concerned about the discoloration of the oral mucosa. On examination, she had pigmentation of her oral mucosa and nails. She had no history of any disease or medication that would cause pigmentation. Although this condition was initially unknown to us, a diagnosis of Laugier-Hunziker syndrome was made. Conclusion: We report a case of Laugier-Hunziker syndrome in an elderly woman, which is not a well-known condition among dental professionals. More knowledge about diseases that cause pigmentation of the oral mucosa would be helpful in dental practice, especially at external facilities.