Epidermodysplasia verruciformis (EV) is characterized by abnormal genetically-determined susceptibility to widespread and persistent infection of the skin with human papillomaviruses (HPV). The infection results in disseminated pityriasis versicolor-like lesions and flat warts. Skin malignant changes are very common and occur on sun-exposed areas. Several treatments have been used but without consistent benefit. Recently, retinoids and alpha-interferon, alone or in combination, have been reported to be of value in the therapy of EV lesions. We present the case of a 43-year-old white female affected by EV who developed multiple squamous cell carcinomas in the oral and genital mucosae during the previous four years. Both wart and cancer lesions harbored HPV24 along with the novel putative HPV type FA51. The patient was treated with a combination of acitretin (0.2 mg/kg per day) and peginterferon alfa-2b (1 microg/kg per week s.c.) for one year, with marked improvement of verrucous lesions and no recurrence of mucosal cancer. Thereafter, interferon was stopped whereas acitretin therapy was continued, but a new Bowen's disease developed in the perianal region, and the acitretin dose was increased at 0.5 mg/kg per day. At six-month follow-up, only a low number of flat warts persisted, and no clinical signs of cutaneous or mucosal carcinoma were evident.