OBJECTIVE: To explore the relationship between cytomegalovirus (CMV), herpes simplex virus (HSV) and human parvovirus B19 (HPV-B19) and fetal malformation. METHODS: There were 16 infants with congenital malformation in the malformation group and 25 normal infants in the control group. CMV, HSV and HPV-B19 infections were diagnosed using the polymerase chain reaction technique (PCR) in the main organs and placentas of the 2 groups. RESULTS: The infection rate with CMV and HSV in the malformation group was 50.0% and 37.5% respectively, compared with the 8.0% and 8.0% respectively in the control group. (P<0.05). The HPV-B19 infection rate didn't differ in the 2 groups. The brain, liver and lungs were the organs most commonly involved in CMV infection, whereas in HSV infection the liver was most commonly involved, with HPV-B19 most commonly affecting the spleen. CONCLUSIONS: CMV and HSV infections are closely related to congenital malformation, but HPV B19 infection is not related to malformation.