As discussed in earlier articles, each infection is capable of producing a wide range of disease in the fetus and newborn infant; however, subclinical presentation is the most common with all except disease caused by herpes simplex viruses, as is best understood. Similarly, maternal infection with these pathogens is often difficult if not possible to diagnose clinically. Moreover, each of the organisms can cause chronic or recurrent infections or both in mothers and their offspring. Thus, the therapeutic problems are obvious. The status of prevention and therapy of infections caused by rubella virus, cytomegaloviruses, herpes simplex viruses, and Toxoplasma gondii will be reviewed. The nature of these infections, particularly time of acquisition, duration, presentation, and long-term outcome, has been detailed elsewhere in this volume. It is this knowledge, then, which provides a foundation for any discussion of prevention and therapy.