There is growing information to support a viral etiology in inverting papilloma formation. Evidence for this hypothesis comes from clinical findings of multicentricity, high recurrence rates, identification of human papilloma virus (HPV), and the presence of viral-like particles within the tumour tissue. Four cases of multicentric inverting papilloma are presented. In one patient, a squamous papilloma (wart) of the nasal vestibule recurred as an inverting papilloma. Another patient also had a cutaneous wart on the right index finger. These cases and others from the literature are discussed with respect to a viral mode of transmission.