Publisher Summary This chapter presents a range of serological methods for the diagnosis of Rubella and congenital Rubella. Detection of rubella-specific IgM remains the method of choice for the diagnosis of both postnatally and congenitally acquired rubella, but isolation of virus and detection of viral RNA by nested reverse transcription-polymerase chain reaction (RT-nPCR) are useful for the diagnosis of congenital rubella in the fetus and newborn infant. Detection of rubella IgM in a serum taken 3–6 days after onset of rash is the method of choice for diagnosis of acute rubella. Although specific IgM may be detected earlier in some patients, this will depend on the assay used. If no specific IgM is detected in a serum taken <6 days after onset, it is advised to collect a second serum a few days later. This should be tested in parallel with the first serum for specific IgM and IgG, as a significant rise in rubella IgG concentration may be detected in addition to rubella IgM. Detection of rubella IgM with IgM-capture techniques is usually a reliable technique for the diagnosis of congenital rubella in the first 3 months of life. However, there is a demand for the evaluation of new techniques for diagnosis of congenital rubella after 3 months in children with deafness only, as they may not present in the neonatal period.