Aims: Lipschütz ulcer (LU), also known as acute vulvar ulcer, is a rare cause of vulvar ulcerations of nonvenereal origin. Our aim is to alert about this manifestation of the disease and to prevent unnecessary treatment.Case description: we present a 15 years old female, without relevant family and past history, admitted in the emergency room with a painful vulvar ulcer, preceded by five days of fever and sore throat. On physical examination, she had enlarged, and erythematous tonsils and bilateral anterior cervical lymphadenopathy and the genital examination revealed vulvar oedema and a deep ulcer with necrotic plaques in labium minus. The exclusion of transmitted sexual disease led to a diagnosis of Lipschütz ulcer. She started symptomatic treatment, oral antibiotic and corticoid therapy. She was discharged from the hospital after 6 days of admission and returned to a consult one month later when it was observed an almost complete resolution of the lesions. No recurrences occurred until 3 months.Conclusion: LU is a misdiagnosed pathology, probably because doctors, in general, are not familiarized with that, and since the diagnosis is made by exclusion. Infectious, such as Epstein-Barr Virus infections, are proposed etiologies.