While a strong association between human papillomaviruses (HPVs) and squamous cell cancers of the female genital tract is known to exist, there is substantial controversy regarding the relationship of HPV with other non-genital carcinomas. Recently there have been some reports focusing on a possible association of HPVs with bronchial carcinomas. These studies mostly used either in situ hybridization (ISH) or the polymerase chain reaction (PCR). In view of these reports, 32 squamous cell carcinomas (SCCs) and six small cell carcinomas of the bronchus were examined for the presence of HPV DNA by both techniques: ISH using 35S-labelled, type-specific probes (HPV 6, 11, 16, 18), and PCR with consensus primers coding for more than 25 different HPV subtypes performed on formalin-fixed, paraffin-embedded material. None of the 38 bronchial carcinomas analysed was positive for HPV DNA, either by ISH or by PCR. On the other hand, additionally examined specimens of 15 cervical carcinomas were positive for HPV 16 DNA in at least three cases by ISH (20 per cent) and in 12 cases by PCR (80 per cent). We conclude that common HPV types do not play an important role in the pathogenesis of bronchial carcinoma.