Viral oncogenes are commonly used to transform and extend the in vitro life span of human epithelial cells. We have established 7 cell lines of human ovarian surface epithelial cells using human papilloma viral oncogenes (HPV-E6E7 ORFs). Cytogenetic analysis of the cell lines revealed a high frequency of telomeric associations ranging from 30% to 100% of the metaphases examined. The short arms of chromosomes 16, 19, 21, and 22 showed a higher rate of telomeric association. Telomeric association with other chromosomal ends appears to be random. Fusion of 2 chromosomes ends may contribute to the genomic instability of transformed cells and lead to further genetic alterations involved in malignant transformation such as gene amplication and loss of heterozygosity. This is the first report describing a high frequency of telomeric associations in human ovarian epithelial cells transformed by HPV oncogenes.