OBJECTIVE: to tell case of pemphigus in oral mucous and to establish diagnosis differential. CASE REPORT: V.C.F., feminine sex, 42 years with bulbous injuries in tongue, palate and patrimonial mucous with evolution have 2 years. Patient presenting intense pain associate the friability of the injuries. Signal of present Nikolsky. Histopathological confirming pemphigus. Injuries: exacerbated for stress. CONCLUSION: importance of the knowledge diagnosis, differentiation with other bulbous injuries for correct treatment.