Detection of HPV by means of in situ hybridization techniques may often present problems if the number of HPV copies is too small, especially when using nonradioactive detection systems. A new way of amplifying extremely small amounts of virus DNA copies is the polymerase chain reaction (PCR), which is mostly used in vitro. In this study, we present a method for in situ PCR combined with immunogold-silver staining (IGSS) and immunoperoxidase (IMP) methods which allows the detection of single copies of HPV-DNA in SiHa cells. This method may have wide applications in routine diagnostic histopathology.