To characterize the risk of malignant progression of cervical epithelial lesions associated with human papillomavirus (HPV) types of yet unknown oncogenic potential the prevalences of these HPVs in different cervical epithelial lesions of 809 patients were determined. HPV types 53, 73, and CP8304 were detected in genital specimens of 16, 22, and 12 of the patients, respectively. The ratio of prevalence in high grade dysplastic lesions or cancers and low grade dysplastic lesions or normal specimens was calculated and compared to corresponding values of well known high-risk (HR) and low-risk (LR) HPVs. For HPV 6, 11, 16, 18, 35, and 73 a ratio of 0.1, 0.2, 5.9, 6.5, 2.5, and 2.4, respectively, was calculated. The ratios of HPV53 and CP8304 were less than 1. Moreover, in contrast to HPV73, these viruses have never been detected in cancer specimens. Thus, HPV53 and CP8304 infections are probably not associated with a high risk of carcinogenesis, while HPV73 could be another HR-HPV type.