Summary: We treated a patient with juvenile xanthogranuloma on the upper lip. A yellow, elastic, hard tumor on the upper lip was evident from birth, which gradually increased in size. The patient was examined at our department at the age of 7 months, at which time the mass extended from the upper lip to the nasal cavity and measured approximately 1 cm. There was a risk that the mass might obstruct the nasal cavity, and an incisional biopsy was conducted to obtain a definitive diagnosis. In histopathological testing, the patient was diagnosed with a juvenile xanthogranuloma. Part of the mass still remains on the upper lip, but has not increased in size during postoperative monitoring. Juvenile xanthogranuloma on the upper lip is extremely rare, and to the best of our knowledge, this is only the fourth case to be reported in the plastic surgery literature in English. In most cases, juvenile xanthogranuloma regresses spontaneously, and unnecessary surgery is to be avoided. The possibility of juvenile xanthogranuloma should always be considered for masses that increase in size in infants and young children, and it is important to reach a definitive diagnosis by skin biopsy.