Primary infections with herpes simplex virus (HSV) and varicella-zoster virus (VZV) may lead to severe illness in pregnancy. Both diseases may be associated with transplacental virus transmission and fetal infection. Such infections can lead to intrauterine death, severe malformations and premature birth; the fetal/congenital varicella syndrome is well-defined. Herpes genitalis and varicella at the time of labor may lead to life threatening neonatal-herpes or varicella of the newborn. Currently neither active immunization nor neutralizing immunoglobulin is available for HSV infections. VZV-seronegative women in child-bearing age can be vaccinated and pregnant women exposed to VZV can be given specific immunoglobulins. While an infection is rarely blocked, the severity is generally reduced. For severe disease antiviral treatment is necessary, with valacyclovir and acyclovir represents the drugs of choice. Primary or recurrent overt disease of the genital tract at the time of delivery an indication for caesarean section. Suppression of recurrent genital herpes during the last weeks of pregnancy with valacyclovir and acyclovir reduces the need for surgical intervention. Neonates exposed to VZV should receive specific immunoglobulin. If neonates show signs of either infection, immediate treatment with acyclovir must be initiated.