An analysis of the data on 52 infants whose mothers had contracted varicella during pregnancy revealed that 27 had congenital malformations ascribed to the maternal varicella infections, while another 25 developed herpes zoster in the early postnatal period. Most of the mothers whose infants had congenital malformations had contracted varicella within the first 20 weeks of gestation, whereas most of the mothers whose infants developed herpes zoster had varicella after 21 weeks of gestation. The clinical features of the various congenital malformations and dysfunctions after maternal varicella were diverse; however, there were peculiar segmental manifestations of anomalies of the skin, the peripheral nervous, the autonomic nervous, and the musculoskeletal systems, all of which receive common innervations from the same levels of the spinal cord. Most other dysfunctions may be ascribed to an encephalitis. Therefore, the mechanism of congenital malformations caused by varicella-zoster virus seems to be due not to fetal varicella but to the development of herpes zoster in utero and to an encephalitis associated with herpes zoster. At least one infant had congenital malformations that were due to maternal herpes zoster infection.