Malignant melanomas of the oral mucous membrane seems an infrequent pathology. They are characterized by a late diagnosis, bad prognosis and a disappointing treatment, because of the difficulties encountered for its total removal owing to complicated accessibility. We report one case of mucous membrane of the mouth in a 56 year-old man, diagnosed and operated in the General Hospital of Specialties "Ciudad de Jaen". The article end with a careful revision of the literature.