The WHO Regional Verification Commission certified in 2017 that Korea was the first country in the WHO Western Pacific Region to achieve rubella elimination. A suspected congenital rubella syndrome (CRS) was reported to the Korea Centers for Disease Control and Prevention in August 2017. The mother of a new-born had visited Vietnam during her pregnancy. CRS was confirmed based on the detection of rubella-specific IgM and rubella RNA in the urine and throat swab. Rubella virus isolated from the throat swab was classified as genotype 2B, and a phylogenetic analysis indicated that this genotype had been imported from Vietnam. This is the first report of CRS confirmed using virus isolation in Korea. Laboratory surveillance plays a critical role in the elimination of rubella through the provision of laboratory testing data, and characterisation of circulating strains.