As a fetal infection occurring during early pregnancy, rubella's potential for teratogenicity is unparalleled. In the postnatal period it is a relatively benign disease. Mumps, on the other hand, causes moderate morbidity and occasional mortality. Both infections cause considerable morbidity and disruption in the lives of young people gathered for group activities. Widespread use of safe and effective live attenuated vaccines has dramatically reduced the incidence of rubella, congenital rubella, and mumps in the United States. Nevertheless, significant numbers of young children, especially in areas of urban and rural immigration and poverty, fail to be immunized in a timely fashion; and some adolescents and young adults remain susceptible either because they escaped immunization in childhood or are primary vaccine failures. These individuals remain the source of individual cases and small outbreaks of rubella and mumps. For total eradication of these infections, we need to intensify vaccine efforts and to maintain surveillance efforts for mumps, rubella, and congenital rubella syndrome.