A plethora of tests for determining the presence of antibodies to varicella-zoster virus (VZV) have been developed over the years, with a wide range of performance standards. There is general agreement that the presence of VZV antibodies in serum indicates immunity to varicella and protection from chickenpox, although the role of specific antibody in mediating protection remains unclear. Both antibodies and cellular immunity probably interact to mediate immunity to the virus. In any case, VZV-specific serum antibody is a useful indicator of protection against chickenpox in patients and persons at high risk of exposure, whether they have been immunized or naturally infected. Serological tests are also a useful implement for evaluating the length of time that immunity to varicella persists after vaccination and whether waning of vaccine-induced immunity occurs. The purpose of this review is to contrast the strengths and weaknesses of currently available VZV antibody assays. Although several of these methods are useful for various specific applications, simpler and more accurate tests to measure antibodies to VZV are a high priority for future research and development.