The generalized form of lichen nitidus (LN) with oral and nail changes is extremely rare in childhood. We report a 10-year-old boy with generalized LN associated with oral involvement and onychodystrophy. Oral lesions showed yellowish papules on the gums. The nails had longitudinal striations and pits on the finger-nails, and transversal ridging of the big toes was found. Cutaneous and mucosal lesions as well as onychodystrophy spontaneously cleared within 8 months.