Colposcopically directed cervical punch biopsies from 362 patients were screened by Southern blot hybridization for the presence of DNA of human papillomavirus (HPV) 6, 10, 11, 16, 18, 31 and 33. The biopsies represented original squamous epithelium, epithelium of metaplastic origin, different stages of cervical intraepithelial neoplasia (CIN) and invasive carcinomas. HPV6/11, 16, 18 and 31 were detected in 2.9% to 13.7% of histologically normal epithelia. HPV6/11 prevailed in CIN I. HPV16 was clearly more abundant than other HPV types in high-grade CIN and invasive cancers (50%-60%), compared with healthy epithelium. Restriction enzyme cleavage analysis of DNA from primary cancers and corresponding metastases proved the stable association of HPV16 DNA with invasive tumor cells. Preliminary follow-up studies of CIN II patients suggested that HPV16-associated lesions are relatively more likely to persist or to progress. Taken together, the data support the notion of a higher oncogenic potential of HPV16.