Human papillomavirus (HPV) infection of the uterine cervices of Japanese women with and without lesions was identified by the filter in situ hybridization method. Exfoliated cervical cells from 23 cervical papillary condylomas, 70 cervical intraepithelial neoplasia (CIN) grade I/II, 26 CIN III, 31 invasive cervical cancers and 666 cervices without evidence of disease (including 53 pregnant women) were tested for the presence of HPV types 6/11, 16 and 18. The positive rates for the detection of HPV types 6/11, 16 and 18 DNA were 47.8%, 26.1% and 8.7% in cervical condylomas, 5.7%, 15.7% and 8.6% in CIN I/II, 0, 34.6% and 0 in CIN III, 3.2%, 38.7% and 9.7% in invasive cervical cancers and 0.9%, 1.8% and 0.6% in the control cervices. These data suggest that, in Japan, HPV6/11, HPV16 and HPV18 infections are also prevalent in cervical cells with normal phenotype, and the type of HPV infection of the uterine cervix is related to the histological diagnosis.