Pemphigus vulgaris is a chronic autoimmune intraepithelial blistering disease with oral mucosal manifestations that very often precede the skin lesions. The vesicles or bullae are produced by an acantholytic process, detachment of differentiating keratinocytes from one another in the epithelial stratum spino sum or spinous cell layer. The pathogenesis of this disease is initially manifested by IgG(mainly) binding to desmosome(desmoglein 3 or 1) in the intercellular spaces of epithelium. This autoantibody binding caused the release of a plasminogen activator(a proteolytic enzyme) from keratinocytes. This ultimately results in cell to cell separation. The mainstay therapy of pemphigus vulgaris is systemic corticosteroids and immunosuppressive agents to eliminate the pathogenic autoantibodies from circulation. A 41-year old woman presented with a 1.5 year history of oral ulceration. There were no lesions on the skin or other mucosal sites. Histology and immunostaining were consistent with pemphigus vulgaris. Control of oral ulceration and normal oral function were achieved after systemic corticosteroids and immunosuppressive agents were instituted.