Human papillomaviruses (HPVs) have been proposed to be the most important etiological factors for cervical cancer although different agents may act in conjunction. Herpes simplex virus type 2 (HSV-2) infection is considered as a possible cofactor to malignant transformation. To examine the influence of HSV-2 infection on the HPV genes expression, CaSki cells bearing 60 to 600 copies of HPV-16 DNA per cell were used as a model system. Twenty hours post HSV-2 infection the mRNA transcripts for HPV-16 early (E1, E2 and E6) and late (L1) genes were analysed by RT-PCR assay. Results indicated that the level of transcription of E1, E2 and E6 genes was up to 3-fold enhanced in HSV-2 infected CaSki cells suggesting that HSV-2 infection could increase the risk of cervical cancer by overexpression of both HPV regulatory and oncogenic genes.