Human papilloma virus (HPV; 16 and 18) is known to play an important etiologic role in cervical dysplasia, but its relationship with anal carcinoma is still unclear. Surgical samples from 80 female patients treated for anal epidermoid carcinoma in the Polyclinic of Surgery in Geneva between 1976 and 1989 were retrospectively studied. Of these, HPV detection was performed in 41 whose DNA was preserved well enough to allow such an analysis. Seventeen (42%) samples contained HPV, with a high percentage of high risk HPV (15/41, 36%). Thirty-eight of the 80 patients had a cervical smear, of which 18% revealed cervical carcinoma. When compared with epidemiological data, the results of this study suggest that genital HPV infection predisposes not only to cervical cancer, but also to anal carcinoma, possibly by means of contiguous contamination.