Pemphigus is a chronic disease with an outcome that is not without risk. It is characterised by loss of the intraepithelial cell-cell relationship (acantholysis). Underlying the disease is an autoimmune disorder in which the desmosomes are damaged by antibodies directed against particular molecules called desmogleins (particularly 3 and 1). Various types of pemphigus have been described with different antibody profiles and clinical signs. In the present paper, a case of pemphigus vulgaris associated with the medication cefaclor monohydrate is reported. Histological and immunological evaluation of the biopsy sample led to a diagnosis of pemphigus vulgaris. The patient, who was not hospitalised, was treated with corticosteroids and systemic immunosuppressors. At present she is being controlled by low doses of systemic corticosteroids. Early diagnosis and the timely introduction of the therapeutic protocol permitted complete remission of the lesions observed at the level of the oral and conjunctival mucosa, preventing the involvement of other locations.