Pemphigus is a group of autoimmune diseases characterized by blistering and / or ulcerative lesions in mucosa and skin. Pemphigus vulgaris (PV) is the most common subtype with an incidence of 0.1 to 0.5 cases in 100.000 people per year throughout the world. The pathogenesis of PV is multifactorial and it is influenced by genetic, environmental and immunological factors. Its incidence has increased in recent years; therefore, early diagnosis is important to reduce the morbidity associated with the disease. In 50-90% of cases, lesions in the oral mucosa represent the first signs of the condition. Thus, the aim of the present paper is to describe a case of PV that was early diagnosed by a team of dentists. Moreover, brief considerations regarding its pathogenesis, clinical aspects and treatment are also provided, including the recent application of the liquid-based cytology as a powerful tool for its diagnosis.