Eosinophilic ulcer of the oral mucosa is a benign, rare, self-limiting, and generally asymptomatic lesion that shows spontaneous regression. Its etiopathogenesis is still uncertain, but trauma seems to play a fundamental role in the occurrence of this tumor. Clinically, this lesion manifests as an isolated ulcer preferentially located on the tongue, showing a raised and indurated border in addition to a white or yellowish bed. Microscopically, eosinophilic ulcer is characterized by an inflammatory infiltrate rich in leukocytes. Since these lesions show spontaneous cure, treatment becomes unnecessary, but in certain cases, cure is obtained by excision of the ulcer during biopsy. In these cases, the differential diagnosis with squamous cell carcinoma is made. A case of very small eosinophilic ulcer of the oral mucosa located on the lateral border of the tongue is presented. Keywords: eosinophilic granuloma, eosinophilic ulcer, oral mucosa, tongue, trauma, traumatic ulcer