The numb chin syndrome consists of unilateral hypesthesia of the chin and lower lip. In adults, it is often associated with metastatic disease to the mandible, base of the skull, or leptomeninges. In children, it has been associated with infiltration of the inferior alveolar nerve by leukemic cells. We describe two cases of numb chin syndrome in children with Ewing sarcoma. In a child with a solid tumor, this symptom seems to have an ominous meaning and should lead to the investigation of progressive skeletal involvement.