Human papillomaviruses (HPVs) are involved in premalignant and malignant skin diseases as well as in a variety of benign cutaneous and mucosal lesion disease. Its association with HPV infection has recently been evaluated in a few studies, but the results are contradictory. For further assessment of the role of HPVs in AK, a series of 100 paraffin-embedded biopsy specimens taken from subjects with AK were studied for the presence of HPV types 1, 2, 3, 4, 5, 7, 12, 15, 26, 36, 37 and 59 DNA using in situ hybridization (ISH) under high stringency conditions (Tm -10 degrees C). All specimens were definitely negative for all bion specimens were definitely negative for all biotinylated HPV DNA probes tested. One fifth of the specimens were studied using the polymerase chain reaction (PCR) with general primers to confirm the negative results. All cases were also in the PCR. Our results suggest that HPVs are not directly involved in the aetiology of AK.