Many nonimmune pregnant women will be exposed to parvovirus B19 infection. Postexposure passive immunization is not currently recommended. Once there is maternal infection, maternal disease is usually self-limited, but the effects to the fetus can be devastating. Even so, additional studies of the risks and benefits of intrauterine therapy such as transfusion and digitalization are necessary before definitive recommendations can be made. Cases where congenital viral infection is suspected should be handled in an appropriate manner and should include serology on mother and infant (both acute and convalescent), viral cultures, and ophthalmologic evaluation. Health care workers must be aware that the infant and its body fluids and organs may be infective to susceptible nursery and laboratory personnel.