Pyostomatitis vegetans is a rare oral disorder with unclear pathogenesis, that may be associated with inflammatory gastro-intestinal diseases, cutaneous involvement or with other disorders of the joints, eyes or liver. The etiology of the extraintestinal manifestations of inflammatory bowel diseases is obscure, but it is believed that the injured intestinal mucosa may trigger immune responses related to inflammatory processes in extraintestinal areas. Oral manifestations include amicrobial pustules and yellow ulcerations with a typical aspect of snail tracts on the bucal and labial mucosa and on the dorsum of the tongue. Histopathological exam shows epithelial acanthosis and superficial ulcerations, as well as eosinophilic and neutrophilic infiltrate in the subjacent connective tissue. Intraepithelial and subepithelial milliary abcesses may also be present. The available therapeutical alternatives (systemic and topical corticosteroids, sulphones, retinoids) have a relatively poor and transitory effect. We present the case of a teenage girl with oral lesions and histopathological features suggestive for pyostomatitis vegetans, persistent for approximately one year, with no other cutaneous or systemic involvement