In a study of 29 cases of histologically confirmed, characterized colposcopically and cytologically, cervical intraepithelial neoplasias 48.3% (14/29) of biopsies were positive for human papillomavirus (HPV) type 16 DNA by polymerase chain reaction. We used two oligonucleotide primer pairs (position 215-514 and 606-805) flanking a 300 and a 199 base pair fragment from the early 6 (E6) and early 7 (E7) genes. The results were concordant both with the E6 and with the E7 regions. Of the amplified products 85.7% (12/14) could be confirmed; these carried 16 specific sequences by Southern blot hybridization. HPV 16 DNA was present in 6.7% (2/30) of the colposcopically directed cytologically normal matched control samples using the same methods.