Lymphocytic choriomeningitis virus (LCMV) is a human zoonosis caused by a rodent-borne arenavirus. It has been associated with both postnatal, as well as in-utero, infection in man. Human infection is acquired after inhalation, ingestion or direct contact with the virus found in the urine, feces and saliva of infected mice, guinea pigs, and hamsters. Congenital LCMV infection should be a diagnostic consideration for infants and children who have chorioretinitis, microcephaly or macrocephaly, hydrocephalus, intracranial calcifications, or nonimmune hydrops fetalis. The diagnosis is made serologically via commercially available immunofluorescent antibody testing. Differentiation of congenital LCMV infection from congenital toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, enterovirus, human parvovirus B19 and syphilis should be made. Further research is necessary to determine the prevalence of this infection in human and rodent populations and to prospectively delineate the spectrum of congenital infection and its consequences. The medical profession, as well as veterinarians and pet shop owners, must educate the public regarding the hazard that wild, pet and laboratory rodents pose to pregnant women.