Pyoderma gangrenosum (PG) is a distinctive ulcerative skin disorder of unknown etiology, associated with an underlying systemic disease in up to 70% of cases. The condition is characterized by the appearance of one or more necrotic ulcers with a ragged undermined violaceous border and surrounding erythema. Lesions are often initiated by minor trauma. The condition can affect any anatomical site, however the head and neck are rarely involved. Although the oral cavity is subject to recurrent minor trauma through everyday activities such as mastication and oral hygiene, as well as during dental treatment, oral lesions appear to be extremely rare. In an effort to provide a detailed explanation of the oral manifestations of PG, a systematic search was conducted using medical databases. A total of 20 cases of PG with oral involvement were reported in the English and French literature. The objectives of this article are to present the pertinent diagnostic criteria and to discuss the differential diagnosis and therapeutic modalities.