Rubella is a contagious virus often causing no more symptoms than a mild cold in children and adults. Its most vulnerable population is the fetus in the womb. Rubella infection during pregnancy may lead to fetal death, fetal birth defects known as congenital rubella syndrome (CRS), growth restriction, or seemingly little to no effects. Birth defects caused by the virus most notably include deafness, heart malformations, and visual problems but can include developmental delays as well. Rubella is not treatable but can be prevented by vaccination. This entry reviews rubella in history and then discusses symptoms and sequelae, concluding with a commentary on rubella in the postvaccination era.