A newly developed general primer-mediated polymerase chain reaction (GP-PCR) was used for the detection of a broad spectrum of Human Papilloma-virus (HPV) genotypes, including unsequenced types, in cytologically normal and abnormal cervical smears and in biopsies of cervical carcinomas. This PCR method used different general primer sets, located in strongly conserved EI and LI regions of the HPV genome. Comparison between results of GP-PCR and HPV-type-specific PCR (TS-PCR) revealed an increase in overall HPV prevalence to 25%, 80% and 88% in scrapes with normally, slightly and severely dysplastic cells, respectively. Unsequenced HPV types were detected in 11% of cytologically normal swabs and in up to 30% of scrapes with dysplastic cells. Further characterization showed that unsequenced types concern HPV 13, 30, 31, 45, 51 and some other, possibly unknown HPV types. More than 90% of carcinomas in situ and invasive cervical carcinomas contained HPV. In the latter, only HPV16 and HPV18 were present. HPV16 was most frequently found in both normal and dysplastic cells, the rate being highest in neoplastic tissue. These results indicate that GP-PCR is a powerful approach for detecting as yet uncharacterized HPV types associated with neoplastic transformation of cervical squamous cell epithelium.