Human cytomegalovirus (HCMV) is the most common cause of viral intrauterine infection. Progress in rapid, specific, and dependable detection of HCMV has recently been achieved by the use of DNA hybridization techniques and other molecular methods. We examined 21 placentas after delivery for the presence of HCMV DNA by polymerase chain reaction (PCR). To test the reliability of the PCR for the detection of HCMV DNA in clinical specimens, two simple PCR assays and a real-time quantitative PCR were used. PCR analysis of villous and decidual cells showed that HCMV DNA was present in 16 placentas (76.2%). Transmission of HCMV infection to chorionic villi was confirmed in 11 organs (52.4%), and congenital infections in newborns were detected in 9 cases (42.8%). These results suggest that HCMV genome detection in placentas at later gestational ages is common. Our results demonstrated that detection of HCMV DNA in placental tissues by DNA amplification provides a specific and sensitive method for diagnosis of intrauterine HCMV infection.