The presence of human papillomaviruses (HPVs) in 38 oral and 16 laryngeal lesions (verrucous hyperplasia, carcinoma in situ and carcinomas) was investigated using the polymerase chain reaction (PCR) technique. All biopsies were fresh frozen and a set of consensus and type-specific primers was used for PCR detection and HPV typing. In oral biopsies a low proportion of HPV-positive cases was found, despite the sensitive techniques. Only one case out of 38, a carcinoma in situ was positive (2.6%). It is thought that this finding reflects a minimal presence of HPV in the oral lesions, but a transient role of virus in the induction of carcinomas cannot be ruled out. Differences in relation to other studies may be geographical and/or methodological. In laryngeal carcinomas (and dysplasias), 3 out of 16 cases were HPV positive. This frequency (19%) concurs with most other studies.