We previously recognized the presence of HPV-DNA in cases of idiopathic neonatal giant cell hepatitis (INGCH) and extrahepatic biliary duct atresia (EBDA) in archivated tissue using the PCR technique. In order to investigate a possible vertical transmission we looked for the presence of HPV-DNA in cervical swabs in the mothers along with formalin-fixed paraffin-embedded hepatic tissue from 3 infants with INGCH and 4 patients with EBDA by nested-PCR. Cervical smears showed koilocytosis consistent with HPV infection in 2 cases. Delivery was vaginal except for one that was by cesarean section. All infants were males. Amplification of HPV-DNA was demonstrated in all cases, the types being concordant in infants and mothers. Although this is a small group, the findings appear in line with previous data. The presence of the same type of HPV-DNA in the infants' livers and their mothers' cervical swabs is another argument supporting the possibility of vertical transmission of the virus.