Pyostomatitis vegetans is a very rare oral manifestation with unknown 
pathogenesis. Skin and other mucous membrane involvement may be seen. This 
lesion has strong association with Inflammatory Bowel Disease (IBD) and may be 
the first sign of it. The management of Pyostomatitis vegetans is usually based 
on the management of underlying bowel disease. We present a case of 
Pyostomatitis vegetans involving gingiva and oral mucosa with no skin lesion 
which led to the diagnosis of Crohn's disease to emphasize important role of 
dentists in diagnosis of rare oral lesions and management of patients' systemic 
disease.